This paper describes an analog circuit design which is different from that of digital chip implementation using matching technology and self-oscillation research and development to drive the welding converter with zero voltage switching. The feedback output voltage is used to control the oscillator frequency to arrive the self-tracking function. Experimental results exhibited that the new analog inverter circuit can be effectively and stably applied on the high power welding system and the the efficiency is higher than that of previous report with IC digital chip design. Ability and stability of the inverter circuit applied to the welding converter are investigated and the adaptability of the final circuit is also didcussed. Due to this kind of study based on the new analog design, it will enhance us to understand the physical realization in this new welding system.
The chelating properties of the hydrazone ligand 2-carboxy-phenylhydrazothenoyltrifluoroacetone (H2L) (2-CPHTTA) have been studied. A series of binary mono nuclear complexes were prepared from the reaction of the ligand 2- CPHTTA with the metal ions, Cd (II), Cu (II),Ni (II), Co (II),Th (IV), and UO2(VI) in the presence of LiOH as deprotonating agent. The binary Cu (II) complex of H2L was reacted with the ligands1,10-phenanthroline or 2-aminopyridine to form mixed-ligand complexes. The binary complexes of Cu (II) and Ni (II) are suggested to have octahedral configuration. The Cd(II) and Co(II) complexes are suggested to have tetrahedral and/ or square planar geometries respectively. The Th(IV) and UO2(VI) complexes are to have dodecahedral geometries, respectively. The mixed –ligand complexes have octahedral configurations. Also, new complexes obtained pyrolytically. The structures of all complexes and corresponding thermal products were elucidated by Elemental analysis, IR and electronic absorption spectra, magnetic moments, 1HNMR and TG–DSC measurements as well as mass spectroscopy. The ligand and some of the metal complexes were found to activate the enzyme pectinlyase.
Introduction\nAlong with the increasing number of dialyzed patients, the number of complications increases. A high-flow accesses may lead to vascular access steal syndrome (VASS) and distal ischemia. The treatment modality of VASS depends on the time when the first symptoms occur.\nThe study presents our experience with revision using distal inflow (RUDI) procedure for high-flow arteriovenous fistulas (AVF).\n\nResults\nThe series involve six end-stage renal disease patients receiving hemodialysis, with autogenous high-flow elbow AVFs supplied by brachial artery. All patients of them underwent RUDI procedure. All patients reported advanced limb ischemia that came along with cold and pale fingers or the entire hand. Other symptoms include not-palpable radial pulse unless access vein was manually compressed, ischemic pain and/or ischemic ulcers and excessive flow through the anastomosis.\nThe goal to achieve was to reduce excessive flow through the access vein and augment the distal flow to the hand.\nDuring RUDI procedure the original arterio-venous anastomosis was ligated, the natural arterial line to the hand was restored. The fistula was reestablished using a bypass from the artery (radial or ulnar) distally from the ligated anastomosis to the access vein. Loss of AVF function following RUDI procedure was not observed.\n\nDiscussion\nThe VASS risk factors taken under consideration include for are brachial instead of distal (radial or ulnar) inflow, diabetes, female sex, peripheral artery disease, age over 60 years and smoking. \nFollowing RUDI procedure ischemic symptoms usually relieved immediately. Autologous vein grafts was used in order to avoid application of any synthetic graft materials and to reduce risk of infection and thrombogenicity. The great saphenous vein provide inflow through a large diameter bridging vein.\n\nConclusions\nThe RUDI procedure effectively reduces ischemic symptoms, restores perfusion to the distal extremity, decreases a high access flow and preserves the AVF for further hemodialysis.
Aim of the study: was to determine the normal range of splenic length, width, thickness and volume in relation to age, gender and body parameters in healthy adult Egyptians.\nMaterials and methods: Five hundred healthy volunteers (250 males and 250 females) without conditions that can affect the spleen or splenic abnormalities. Patient’s age, gender and physical parameters (height, weight, body mass index (BMI), Body Surface Area (BSA) and body fat) were recorded. Abdominal ultrasonography was done to determine splenic length, width and thickness and spleen volume calculated. \nResults: There was the highly significant difference between males and females in all splenic parameters including splenic length, width, thickness and volume with the mean values were higher in males (180.6 cm2) than that in females (166.3 cm2). The splenic volume showed significant correlation with age, body height, BMI and BSA in both genders while it showed significant correlation with body weight and body fat in females only.\nConclusion: By the end of this study, we concluded that all splenic parameters were highly correlated with body height and BSA in males. In females, all splenic parameters were highly correlated body fat and BSA.\nKey words: Ultrasonography – Splenic Volume – Body Surface Area – Body Mass Index.
Cadmium (Cd) is an environmental cumulative pollutant affects many organs specially liver. Recently, plants possessing medicinal activities are investigated in mitigating hepatotoxicity. Pomegranate fruit has been intensively utilized as natural remedy in many cultures. The effect of methanolic extract of pomegranate peels (PEE) against cadmium hepatotoxicity in mice is evaluated. Forty mice were used in this study. Animals were divided into four groups, the 1st control group was given saline solution, the 2nd group was orally treated with 50 mg/kg/b.w. of methanolic pomegranate peels extract (PPE), the 3rd group was i.p injected with 2 mg/kg/bw of CdCl2, and the 4th group was injected with 2 mg/kg/bw of CdCl2 followed by oral administration with 50 mg/kg/b.w. PPE. Histopathological changes of liver were examined by light and transmission electron microscopes. Serum ALT and AST was determined and oxidative stress markers MDA, total antioxidant capacity (TAC) were measured in liver homogenate. The results showed that Cd induced several histological alterations in the liver including congestion of blood vessels, leucocytic infiltration, cytoplasmic vacuolation of the hepatocytes and fatty infiltrations. The ultrastructural changes include mitochondrial degeneration, swelling of rER and pyknosis of nuclei with increase in fat droplets and lysosomes. Biochemically, ALT and AST activities and MDA were increased levels while TAC was decreased. Treating mice with PEE with Cd improved the histological as well as ultrastructural structures. ALT, AST and MDA were reduced with increase in TAC. The results suggested that the ameliorative effect of PPE may be due to its antioxidant properties in combating free radical-induced oxidative stress and tissue injury resulting from cadmium chloride exposure.
Objective: The precise knowledge of the root canals and pulp chamber morphology - and its possible variation - is crucial for a successful endodontic therapy. Despite the low incidence of root canals variation in mandibular premolars, it is important to consider the atypical canal pattern possibly found. Case report: This report presents a case of a patient with right unilateral anatomical variation. Right mandibular first premolar with three canals, and the second with two. Periapical radiograph suggested the presence of more than one root canal, but the variation was only confirmed after the endodontic access and the pulp chamber floor inspection. Cleaning and shaping of the canals was performed through the HyFlex® CM Rotary Files System (Coltene). After the root canal obturation, it was possible to see through the post radiograph, the anatomy discussed. Conclusion: Therefore, it is important to highlight the possibility of these variations and thereby, reinforce the need for internal anatomy knowledge in order to perform an appropriate endodontic treatment.
This study was aimed at identifying a broad spectrum bio-insecticide used to control insects of medical and agricultural importance as Culex pipiens and Spodoptera littoralis. Six actinobacterial isolates were recognized from different soils in our Egyptian habitat. One Streptomyces isolate proved its toxicity to larval stages of both pests, recording LC50 values as, 5.02 ± 1.58 ml/100 ml for Culex pipiens and 7.84 ± 2.3 ml /100ml for Spodoptera littoralis.\n Morphological and histopathological abnormalities appeared after larval treatment were recorded. The delayed effect on pupal and adult stages was also visualized. \n 16S-rRNA gene analysis and sequencing proved that our isolate had about 100 % similarity with Streptomyces griseoflavus.
Research Aim(s):This project builds and investigation about the difference in the role, impact and influence of mosques and churches in past and present. Moreover, it tries to distinguish the reason of the gap between their roles if it exists.\nResearch Importance/Contribution:The importance of this study comes from its ability to construct a clear and comprehensive understanding about the roles of mosques and churches in past and present. This study can be an important building block for other studies, it can direct other investigators towards understanding how Islam and Christ civilizations have changed from past to present.\nResearch Methods:Both qualitative and quantitative methods were used in this research, a structured questionnaire was built in order to study the impacts of mosques and churches and how do they differ from the past till now. Fifty participants were involved in this study and structured interviews are made in order to develop a detailed scene.\nResearch Findings:In general, the function of mosques and churches is different and has changed from what it was in the pastThis study revealed that there is a decreasing role of mosques nowadays in comparison to their role in the past. The role of the church hasn’t changed a lot from its role in the past; this may require more investigation in the future.
The purpose of this study was to examine the application validity of the visual information occlusion method for improved balance in the elderly by comparing the differences in balance between visually disabled individuals and individuals with normal vision. We measured static balance and dynamic balance by group. Visual disability 10 and normal men 10 with age ranging from 60 to 65 participated in the experiment as subjects, and were measured static and dynamic balance from each participants’. Static balance measurements were conducted by examining the participants’ ability to stand on one foot first with their eyes closed and then open. The results, obtained after analyzing the differences in static balance between the groups and with an absence of visual information, showed significant interactions between the groups and test conditions. The posteriori test showed that in the preferred limbs condition visually disabled participants exhibited a higher static balance than participants with normal vision. The of suggest that an absence of visual information due to visual disability lead to compensatory actions in other sensory organs, which improves proprioceptive and vestibular sensitivity. Therefore, practicing balance through visual occlusion could be utilized as an effective physical intervention for improving balance among the elderly.
Moringa and especially Moringa oleifera is worldwide valued due to its properties. One of the useful parts of the tree is the seed. The extraction of seed kernel oil from Moringa oleifera, Plain variety of Cuban origin is evaluated. The extraction percentage of oil is set as the dependent variable in the design of experiment. The studied factors (particle size, solvent-seed ratio and type of solvent interaction term) significantly influenced the dependent variable. The best condition for the extraction of oil was achieved with solvent-seed ratio (6:1), using hexane and milled seeds. The physicochemical characterization of the oil was in agreement with literature reports. Based on the profile of fatty acids, a predominant 74.72% of oleic acid was achieved, followed by palmitic, behenic and stearic acid (4.46%). The paper discuss about the potential of the oil for biodiesel production.
The north-eastern of Algeria has numerous mineralized showings and economic ore-deposits, including principally lead, zinc, copper, iron, barite, mercury and antimony. Currently, geological and gitological data are in digital or analog data form. To manage all this data, GIS has become an essential platform to store, organize and analyze all the geoscience data. With Arcgis support, the resulting geographic information system has allowed us a database named \"northeastern_algeria_mineral_ deposits_Geodatabase\", structured according to several categories and interoperable classes of information (topography, lithostratigraphy, tectonic, ores-deposits, showings and mineralized points... etc.). \nAnalysis and processing of spatial data have allows the design of different geo-referenced geological maps, including ore-deposits, showings and mineralized points at different scales (especially at 1.500 000). These combined supports define different mineral potential zones, different geological environments and directional axes controlling mineralization of this region.\nThis system offers an editing possibility of several cartographic materials, a better vision for the distribution of mineralization and updating easily the geoscience data. It also represents a reference for future geological and mining exploration.
Like water, air or clay, normal water-salt regime of soils is very important for the well-functioning of pedosphere. The economic activities, like the exploitation of natural resources are also very important for our daily life. In this complex environmental context, the intensive exploitation of oil and gas increase high ecological danger and therefore can lead to land contamination.\nOur research presents a set of correlation and regression chemical analysis of the main ions concentration in the anthropic technosoils resulted from oil industry in regions Ohtyrsk and Poltava, Ukraine. According to the research, the empirical equations was received.\nThe environmental informatics systems, quest for possibilities to modeling dependencies of toxic salts from soils in industrial oil regions, with high and high accuracy. The obtained correlations, can be used in the analytical studies of soil samples, modeling of salts dissemination in soil, development of measures for soil restoration, calculation needed amounts of subsidiary chemicals for salty soils restoration.
Green wall is a promising technology and a new design strategy for sustainable building, considered a solution for modifying the urban microclimate and mitigating urban heat island by minimizing the continuous rising temperature in city cores and dense areas, the space available for greening is very limited and green wall can be applied to the exterior facades of the buildings. The study aims to provide with the impacts of the green wall thermal performance for building in dense area of Amman like the university of Jordan street-Queen Rania Al-Abdullah street and count thermal advantages bring by green wall system in comparison to the existing conventional system, the study suggests a green wall building façade design for the existing buildings front of the main gate of university of Jordan side of mixed use building, based on the computer simulation results for the existing construction. The results indicated that the effect of green wall on the building façade succeeds in lowering the urban heat island effects and enhancing comfort at the urban level, reducing the external temperature in dense urban areas, this could be generalized to dense areas where the climatic conditions and building characteristics are quite similar to the study area in this paper.
High mobility group box 1 (HMGB1) is a ubiquitous nuclear and cytosolic protein that was shown recently to be a mediator of lethal systemic inflammation. Inhibition of HMGB1 release into the circulation ameliorates systemic inflammatory diseases in preclinical animal models. We show here that curcumin, a natural polyphenolic product, regulates the cellular responses in inflammation and thereby provides potent protection against endotoxemia. First, treatment of murine RAW264.7 macrophages with curcumin significantly inhibited their lipopolysaccharide (LPS)-induced release of HMGB1. This effect associated with inhibition of nitric oxide (NO) formation and inducible NO synthase (iNOS) expression. The ability of curcumin to inhibit HMGB1 release by macrophages was significantly potentiated by L-NMMA, a specific NOS inhibitor. Thus, curcumin inhibited HMGB1 release by suppressing the NO signaling pathway. This inhibitory activity was mediated by suppressing LPS-induced c-Jun N-terminal kinase activation. By contrast, although LPS upregulated extracellular signal-regulated kinase and p38 activation in RAW264.7 cells, neither activation was suppressed by curcumin. Second, administration of curcumin improved the survival rate of endotoxemia model mice. This associated with reduced circulating HMGB1 levels and tissue expression of iNOS. Thus, curcumin has therapeutic potential in systemic inflammatory diseases, as it can downregulate inflammation by inhibiting the NO/iNOS-dependent release of HMGB1 by macrophages.
Objective To explore the possible invasive effect of four microRNAs in invasive pituitary adenomas. Design Based on our previous studies, several in silico algorithms, and relative literatures, 30 Han Chinese patients with invasive pituitary adenomas and 30 with non-invasive pituitary adenomas were involved in this research. The proteins related to invasion underwent immunohistochemical staining, including basic fibroblast growth factor (FGF2), pituitary tumor transforming gene (PTTG), cyclin B1 (CCNB1), survivin, focal adhesion kinase (FAK), and microvessel density (MVD). To validate the effect of microRNAs, miR-24, miR-93, miR-126, and miR-34a were chosen as possible targets for the aforementioned proteins with four in silico algorithms. All microRNAs tests were performed using quantitative real-time polymerase chain reaction (qPCR). The expression levels of proteins and microRNAs associated with tumors’ invasiveness were analyzed. Results In our study, FGF2, FAK, PTTG, CCNB1, and MVD were overexpressed in the invasive group compared with the non-invasive group, while an increase in the expression of survivin in the invasive group did not achieve statistical significance. This paper reviewed the literature, and four microRNAs involving invasion were selected for study: miR-24, miR-34a, miR-93, and miR-126. Under-expression of miR-24, miR-34a, and miR-93 was significant in the invasive group, while a decrease of miR-126 expression in the invasive group did not achieve statistical significance. Conclusion FGF2, PTTG, CCNB1, survivin, FAK, and MVD proteins of pituitary adenoma showed strong expression in invasive tumors. Furthermore, miR-24, miR-93, miR-34a, and miR-126 were under-expressed in invasive Pituitary adenomas compared with non-invasive ones. The results indicated some relationship between the miRNA and protein expression during the pituitary invasion process.
Concentrations of the heavy metals (Fe, Zn, Pb, Cu, Cd and Co) were assessed in water, sediment and the soft tissues of three length classes of the edible bivalve Venerupis decussata. The specimens were collected monthly from the Egyptian Mediterranean Sea coast of Port Said city during the period from December 2015 to November 2016. The mean concentrations of heavy metals in water were 4.44, 0.06, 0.04, 0.44, 0.54 and 0.45 for Fe, Zn, Pb, Cu, Cd and Co μg/L, respectively. The corresponding concentration values in the sediment were 21.7, 6.33, 0.55, 10.65, 2.30 and 1.39 μg/g dry weight for Fe, Zn, Pb, Cu, Cd and Co, respectively. However, these metals were assessed in the soft tissues of three length classes of V. decussata. A negative relationship between the bivalve size and metal concentration was identified, which states that the smallest individuals contained the highest concentrations of metals. Food quality and uptake of heavy metals in tissues of V. decussata generally varied along size gradients, with peak values in small-sized individuals. The possible public health threats from dietary exposure to the heavy metals were evaluated.
Copper oxide and cobalt oxide (Co3O4 , CuO) nanocrystals (NCs) have been successfully prepared in a short time using microwave irradiation. Copper nitrate and cobalt nitrate were used as stating materials for preparing the Co3O4 and CuO nanocrystals, respectively. Distilled water was used as a solvent for both oxides. The resulted powders of nanocrystals (NCs) were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Thermogravimetric analysis (TGA), Fourier-transform infrared (FT-IR) and UV–visible absorption spectroscopy of the investigated nanoparticels are illustrated. The obtained results confirm the presence of the both of oxides nanopowders produced during chemical precipitation using microwave irradiation. TEM results have shown that the obtained nanocrystals contain high dispersion and narrow size distribution. The results of x-ray diffraction confirm those obtained from the transmission electron microscope. Optical absorption analysis indicated the direct band gap for both kinds of nanocrystals.
Background: Phenol and its derivatives constitute widespread water pollutants. They have been found to accelerate tumor formation, cancer and mutation. Material and Methods: In this work, walnut shell residue has been used as a raw material in preparation of powder activated carbon by the method of chemical activation with zinc chloride for the adsorption of phenol from dilute aqueous solutions. The influence of the mass impregnation ratio (R= Zncl2/walnut shell) and physical activation by the CO2 stream on the physical and chemical properties of the prepared carbons was examined. The effects of main parameters such as contact time (t), initial phenol concentration (Co) and solution\'s pH were studied on phenol adsorption. Results: The results show that CO2 activation has two effects on phenol adsorption, the first one consists of developments in pore size distribution which resulted in increasing in pore structure heterogeneity, further; CO2 activation by creating COOH functional groups on the surface of porous media and blockade of these areas decrease physical adsorption against chemical adsorption. The maximum uptake of phenol at 25oC was 214 mg/g at pH near phenol pKa and Co=1000 mg/l. All data were fitted well with Langmuir isotherm, but after CO2 modification, deviation from Langmuir shows that both physical and chemical adsorption occurred during adsorption. The kinetic data were fitted to different models such as pseudo-first order, pseudo-second order and diffusion model. Pseudo-second order model has been chosen as the best model. Conclusion: In overall, walnut shell shows excellent adaptive characteristics for the removal of phenol and appears as a very promising sorbent due to its high uptake capacity and to its low cost.
Objective: The aim of this study is to evaluate the effects of caffeined coffee on intraocular pressure (IOP), diastolic blood pressure (BP), and heart rate (HR). \nMethods: This study conducted a prospective survey. We analyzed the IOP, diastolic BP and HR for hour 1,2, and 3 after drinking caffeined coffee in the morning (8:00AM) and mid-night (11:00PM). During this period, 600 male volunteers were enrolled and they all take part in experiment 1 and 2. All subjects were divided into 2 groups. One group (300 people) drank one cup coffee(150 caffeine in total 160 mL hot water) and other drank two cups (300 mg in total 320 mL water water) by random. In experiment 1, 300 subjects drank one cup coffee and 300 volunteers drank two cups at 8:00AM and 11:00PM and then checking the above three parameters. In experiment 2, 600 subjects consuming one and two cup in the same time. Afterwards, the same procedures were repeated as the experiment 1. \nResults: There are no remarkable changes in the morning. As to the changes of IOP, the elevated magnitude of IOP was about 6-8 mmHg after coffee intake. Besides, the mean diastolic BP even elevated to 98.7 ~ 101.1 mmHg after caffeine intake. Furthermore, the HR may reach to 89.5 and 90.2 (amplitude: 15/min) after consuming coffee for 2 hours. According to our series of study, we found that the caffeine-inducing elevation of IOP, diastolic BP and HR was apparent significantly at midnight than morning. Besides, the duration of impacting effect is almost 2 hours. \nConclusion: This is the first one article to evaluate the effect caffeine at mid-night in the world. Many people are used to drink caffeine coffee at midnight to concentrate on their work and even activity in Taiwan. However, they didn’t know the associated higher IOP, diastolic BP and HR which are the risk factors of glaucoma, cardiovascular disorders, stroke and even death. Therefore, we must remind the public for the correct study as soon as possible
Background: Coarctation of the aorta (CoA), which was first described by Morgagni, accounts for 5-7% of all congenital heart diseases. Since the first successful surgical repair was performed in 1944 by Crafoord, several methods including operatory and transcatecter were developed with excellent results. Purpose: The six-year follow-up of the hybrid treatment of recoarctation with pseudoaneurysm on the suture line requiring the third surgical intervention was analyzed by means of combined procedures between the endovascular and conventional approaches. It is in this concept that we treat the patient in this brief communication. Results: After a 6-year follow-up of the hybrid treatment, the patient remains asymptomatic since the surgery performed in early 2011. He maintains blood pressure levels within normal limits with an intermediate dose of beta-blocker. The echocardiogram presents grade I diastolic dysfunction, concentric hypertrophy of discrete-grade walls with a residual gradient in the thoracic aorta of 20 mmHg. Aortic insufficiency of minimal degree, mitral insufficiency of discrete degree and tricuspid insufficiency of discrete degree. The findings of angiotomography of the thoracic aorta revealed good permeability of the ascending thoracic aorta with maximum transverse diameter within normal limits. Aortic arch with normal dimensions presenting edentures in distal segment compatible with post-surgical status. Presence of endoprostheses with metallic structure throughout the descending thoracic aorta beginning at the level of the ostium of the left subclavian artery that is occluded. Good permeability of brachycephalic trunk and left common carotid artery. Conclusion: After 6 years, the patient is asymptomatic. Computed tomography and angiography demonstrated well-positioned endoprostheses, without leakage, pseudoaneurysm exclusion, and absence of signs suggestive of pleuropulmonary alteration. The complexity of this case reaffirms the use of the hybrid treatment and the importance of the Heart Team.
Laser induced generation of hydroxyl radical (OH•) from H2O2 is dependent on the concentration of H2O2, irradiation time and the source of the laser as the He-Ne yellow light is less effective in generation of OH• compared with the plasma or halogen lamp. The aim of this study is to show the interaction between the OH• radical that generated from H2O2 and the irradiation that emitted from He-Ne laser (632.8 nm wavelength) on the calf thymus double strands DNA (ctdsDNA) molecules using a simple in vitro experimental model. A known concentration of ctdsDNA solutions was subjected to the irradiation with He-Ne laser (632.8 nm) in the absence or presence different concentrations of hydrogen peroxide (H2O2) up to 60 seconds. The levels of nucleic acid that released as uncontaminated and contaminated proteins were used as markers of DNA damage in terms of hypochromasia (DNA breakage) and hyperchromasia (separation of DNA strands). Helium-Neon laser (632.8 nm) irradiation induced hypochromasia effect in the uncontaminated protein while hydrogen peroxide induced a remarkable hyperchromasic effect. In the contaminated protein. He-Ne laser (632.8) as well as hydrogen peroxide induced hyperchromasic effects. Inconsistent findings were observed when the DNA molecules treated with hydrogen peroxide and simultaneous exposure to the laser irradiation. In conclusion,He-Ne laser light (632.8 nm) irradiation for short time exerts minor significant effect on the DNA molecule, and it does not protect the DNA molecule from the free radicals that generated from hydrogen peroxide. \nKey words: Calf thymus double strands DNA, Helium-Neon laser, Hydrogen peroxide, Hypochromasia, Hyperchromasia
The problematic of cereal production in Algeria raises three determinants factors: climatic, edaphic and agronomic. To face up to this situation, conservation agriculture offers an opportunity to reverse this alarming trend. To release an at the same time productive and sustainable system of production. A culture of soft wheat was set up to see them behavior of two tillage systems [no-tillage (NT) and conventional tillage (CT)]. For this objective, two experiments have been realized between 2012 and 2014, at the site of Mazagran - Mostaganem (west of Algeria). The obtained results have concluded that the CT has positive effects on the culture of soft wheat in terms of precocity in lifting date and maturity date, in number of tillers/m², in aerial biomass produced, and especially on yield and its components except the number of spikes/m² and thousand grain weight. As against the NT show dominant with a slight difference in thousand grain weight.\nKeywords: Soft wheat, no-tillage, conventional tillage.
The purpose of this research is to study the effects of different truss shapes (in term of truss weight) in the design of plane truss using angle section. The need of this study arises where sometimes it is difficult or taking much time to choose an effective and economical truss shape during the design period. In investigating the effectiveness of various truss shapes, a total of 48 truss shapes with simply pinned supports are chosen. The design loads are distributed to the joints so that there is no moment to be resisted by the members. A total of five set trusses (48 trusses) with different span and depth were analysed and designed with the aid of STAADPro. The analysis of all sets of trusses enables comparisons to be made among the various spans, depths and depth over span ratios of trusses. Optimal trusses from each set of trusses are to be compared to determine whether the effective shapes are the same for different spans and depths. The selfweights obtained from the STAADPro are then converted into masses (kg) which are used in calculating the costs of materials. This study shows that there is no certainty in determining the most effective shapes neither with same span, depth nor depth over span•ratio. The most effective truss shape is actually specific for every truss span and depth. However, close results might be obtained where it does help to provide a good guideline in choosing a truss that does not waste much material. Thus, this method to determine the effective trusses is acceptable and can be furthered for future researches.
