102 research outputs found
Comparative Study on the Automated Warehouse with Cartesian Robot Using PLC and Arduino
Nowadays, automation system is necessary in every warehouse. It can assist operators in easily managing warehouses furthermore reduce unexpected errors from humans and surrounding environments. Nevertheless, a number of control methods have been available for the warehouse system. Each method has advantages and disadvantages considered regarding ease of use, stability as well as cost-effectiveness, etc. Therefore, in order for comparative performances of control algorithms between the PLC and the Arduino, the models of automatic warehouse with PLC and Arduino boards are implemented in this paper. The comparative results show that the average time difference between two methods is 7% with Arduino being faster and lower cost rather than PLC. This ability of using microprocessor as the Arduino board presents some advantages even lesser stability. Thus, alternative methods with current and higher technological devices are possibly selected instead of the old-fashion control algorithm in order to gain more benefits and advantages. Furthermore, integration of the ROS with an automation unit to upgrade an existing system have currently been conducted on the warehouse system to evaluate and compare the system’s performances. The results will be presented in a separated paper
End-mill carbide tool wear in machining metallic biomaterial
Machining of metallic biomaterials causes a slew of issues, including cutting tool wear and poor surface quality owing to inefficient tool design, which leads to excessive heat output. The objective of the research is to evaluate the wear of developed of uncoated carbide endmill tool with rake angle varied from positive to negative value in dry machining Stellite 21. The fabricated endmill is tested at Fanuc Robodill α-T14iFb with cutting conditions parameters are kept constant; including cutting speed (Vc): 60 m/min, feed rate (f): 153 mm/rev, and depth of cut (ap): 0.2 mm, throughout the cutting trials. The accuracy of fabricated endmill, wear mechanism, cutting force, and surface roughness were measured using Dino-Lite Microscope, Scanning Electron Microscope, Neo-Momac Dynamometer and Mitutoyo Surface Profiler, respectively. The result shows that by using a positive rake angle, the phenomenon of tool wear is reduced, and directly reducing the surface roughness and cutting force. Based on energy dispersive x-ray (EDX) element analysis, presence of oxygen in the cutting process which indicates the occurrence of oxidation wear on cutting tool. Extended observation of wear mechanism show high content of chromium on the flank face is revealed that indicated the diffusion wear on tools has occurred. In conclusion, the enhancement of tool geometry of endmill cutting tool is a key step toward sustainable manufacturing of high-end applications in biomedical industries
A Mini Review on Working Mechanism, Standard Operating Procedure (SOP) and Preventative Maintenance of Low Temperature Long Term (LTLT) Milk Pasteurizer
A small-scaled batch Low Temperature- Long Term (LTLT) pasteurizer is one of many types of pasteurizers that is being utilized in food-based industries particularly in dairies. It has a capacity of heating up the milk and holding the temperature for a certain amount of time to kill pathogenic microorganisms. The instantaneous heat up is caused by heat exchangers either in the form of plates or metal coils depending on the machine. The coil is circulated within the jacket of the tank where it heats up and holds the temperature. Hot water circulation will be in continuous movement around the milk to heat it up and maintain the desired temperature. After certain period, the efficiency of LTLT pasteurizer starts declining due to cumulated issues. Decline in efficiency will affect the output of the machine too. Instantaneous heat exchanges, leaking, unstable pressure and electrical problem degrades the machine over period if it is not complying with Standard Operating Procedure (SOP) and a proper Preventative Maintenance (PM) plan. The SOP and PM will increase the machine’s lifespan and maintain a good efficiency rate for longer period. This mini review paper will compile the possible PM plan and establish a sustainable SOP for the LTLT Pasteurizer
Electrochemical Deposited Nickel Nanowires: Influence of Deposition Bath Temperature on the Morphology and Physical Properties
This paper investigates the influence of the electrolytic bath temperature on the morphology and physical properties of nickel (Ni) nanowires electrochemically deposited into the anodic alumina oxide porous membrane (AAO). The synthesis was performed using nickel sulfate hexahydrate (NiSO4.6H2O) and boric acid (H3BO3) as an electrolytic bath for the electrochemical deposition of Ni nanowires. During the experiment, the electrolyte bath temperature varied from 40°C, 80°C, and 120°C. After the electrochemical deposition process, AAO templates cleaned with distilled water preceding to dissolution in sodium hydroxide (NaOH) solution to obtain free-standing Ni nanowires. Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive Spectroscopy (EDX) and X-ray Diffraction (XRD) analysis were employed to characterize the morphology and physical properties of the synthesized Ni nanowires. Finding reveals the electrodeposition bath temperature significantly influences the morphology and physical properties of the synthesized Ni nanowires. Rougher surface texture, larger crystal size, and longer Ni nanowires obtained as the deposition bath temperature increased
A comprehensive review of hydroxyapatite-based coatings adhesion on metallic biomaterials
Metallic biomaterials have been employed in replacing and reconstructing the structural parts of the human physical structure due to their high mechanical properties, superior biocompatibility, and high corrosion resistance. The most common metallic biomaterials that have been used in implants include magnesium, stainless steel, cobalt-based alloy, titanium, and titanium-based alloy. Hydroxyapatite (Ca10(PO4)6(OH)2) is one of the ceramic biomaterials considered as ideal materials for coating on metallic biomaterials as it possesses almost the closest similarity in chemical composition and excellent biocompatibility with natural bone tissue. Recently, the HAp-based coating has increasingly drawn attention to improve the adhesion quality in metallic biomaterials. This study comprehensively reviews the current progress in the adhesion qualities of HAp-based coatings on metallic biomaterials specifically for the biomedical application. It has been observed that a surface that meets the minimum unique characteristics will enhance the bonding force between the coating and metallic biomaterial as the substrate. Critical factors of coating/substrate materials, coating techniques, and coating thickness that determine the adhesion quality are thoroughly identified and discussed. The surface structure and microstructure of HAp-based coating are also reviewed to confirm the findings
Prediction of Cutting Force in End Milling of Inconel 718
This paper presents the effect of cutting parameters on the cutting force when machining Inconel 718. Response surface methodology (RSM) was used in the experiment, and a Box–Behnken design was employed to identify the cause and effect of the relationship between the four cutting parameters (cutting speed, feed rate, depth of cut and width of cut) and cutting force. The ball-nose type of end mill with donwmill approach was maitained througout the experiment. The forces were measured using Kistler dynamometer during straight line machining strategy. The result shows that the radial depth of cut was the dominating factor controlling cutting force, it was followed by axial depth of cut and feed rate. The prediction cutting force model was developed with the average error between the predicted and actual cutting force was less than 3
Comparative study between wear of uncoated and TiAlN-coated carbide tools in milling of Ti6Al4V
As is recognized widely, tool wear is a major problem in the machining of difficult-to-cut titanium alloys. Therefore, it is of significant interest and importance to understand and determine quantitatively and qualitatively tool wear evolution and the underlying wear mechanisms. The main aim of this paper is to investigate and analyse wear, wear mechanisms and surface and chip generation of uncoated and TiAlN-coated carbide tools in a dry milling of Ti6Al4V alloys. The quantitative flank wear and roughness were measured and recorded. Optical and scanning electron microscopy (SEM) observations of the tool cutting edge, machined surface and chips were conducted. The results show that the TiAlN-coated tool exhibits an approximately 44% longer tool life than the uncoated tool at a cutting distance of 16 m. A more regular progressive abrasion between the flank face of the tool and the workpiece is found to be the underlying wear mechanism. The TiAlN-coated tool generates a smooth machined surface with 31% lower roughness than the uncoated tool. As is expected, both tools generate serrated chips. However, the burnt chips with blue color are noticed for the uncoated tool as the cutting continues further. The results are shown to be consistent with observation of other researchers, and further imply that coated tools with appropriate combinations of cutting parameters would be able to increase the tool life in cutting of titanium alloys
High Diversity of Cryptosporidium Subgenotypes Identified in Malaysian HIV/AIDS Individuals Targeting gp60 Gene
BACKGROUND: Currently, there is a lack of vital information in the genetic makeup of Cryptosporidium especially in developing countries. The present study aimed at determining the genotypes and subgenotypes of Cryptosporidium in hospitalized Malaysian human immunodeficiency virus (HIV) positive patients. METHODOLOGY/PRINCIPAL FINDINGS: In this study, 346 faecal samples collected from Malaysian HIV positive patients were genetically analysed via PCR targeting the 60 kDa glycoprotein (gp60) gene. Eighteen (5.2% of 346) isolates were determined as Cryptosporidium positive with 72.2% (of 18) identified as Cryptosporidium parvum whilst 27.7% as Cryptosporidium hominis. Further gp60 analysis revealed C. parvum belonging to subgenotypes IIaA13G1R1 (2 isolates), IIaA13G2R1 (2 isolates), IIaA14G2R1 (3 isolates), IIaA15G2R1 (5 isolates) and IIdA15G1R1 (1 isolate). C. hominis was represented by subgenotypes IaA14R1 (2 isolates), IaA18R1 (1 isolate) and IbA10G2R2 (2 isolates). CONCLUSIONS/SIGNIFICANCE: These findings highlighted the presence of high diversity of Cryptosporidium subgenotypes among Malaysian HIV infected individuals. The predominance of the C. parvum subgenotypes signified the possibility of zoonotic as well as anthroponotic transmissions of cryptosporidiosis in HIV infected individuals
Combination of searches for heavy spin-1 resonances using 139 fb−1 of proton-proton collision data at s = 13 TeV with the ATLAS detector
A combination of searches for new heavy spin-1 resonances decaying into different pairings of W, Z, or Higgs bosons, as well as directly into leptons or quarks, is presented. The data sample used corresponds to 139 fb−1 of proton-proton collisions at
= 13 TeV collected during 2015–2018 with the ATLAS detector at the CERN Large Hadron Collider. Analyses selecting quark pairs (qq, bb,
, and tb) or third-generation leptons (τν and ττ) are included in this kind of combination for the first time. A simplified model predicting a spin-1 heavy vector-boson triplet is used. Cross-section limits are set at the 95% confidence level and are compared with predictions for the benchmark model. These limits are also expressed in terms of constraints on couplings of the heavy vector-boson triplet to quarks, leptons, and the Higgs boson. The complementarity of the various analyses increases the sensitivity to new physics, and the resulting constraints are stronger than those from any individual analysis considered. The data exclude a heavy vector-boson triplet with mass below 5.8 TeV in a weakly coupled scenario, below 4.4 TeV in a strongly coupled scenario, and up to 1.5 TeV in the case of production via vector-boson fusion
Canagliflozin and Renal Outcomes in Type 2 Diabetes and Nephropathy
BACKGROUND Type 2 diabetes mellitus is the leading cause of kidney failure worldwide, but few effective long-term treatments are available. In cardiovascular trials of inhibitors of sodium–glucose cotransporter 2 (SGLT2), exploratory results have suggested that such drugs may improve renal outcomes in patients with type 2 diabetes. METHODS In this double-blind, randomized trial, we assigned patients with type 2 diabetes and albuminuric chronic kidney disease to receive canagliflozin, an oral SGLT2 inhibitor, at a dose of 100 mg daily or placebo. All the patients had an estimated glomerular filtration rate (GFR) of 30 to 300 to 5000) and were treated with renin–angiotensin system blockade. The primary outcome was a composite of end-stage kidney disease (dialysis, transplantation, or a sustained estimated GFR of <15 ml per minute per 1.73 m 2), a doubling of the serum creatinine level, or death from renal or cardiovascular causes. Prespecified secondary outcomes were tested hierarchically. RESULTS The trial was stopped early after a planned interim analysis on the recommendation of the data and safety monitoring committee. At that time, 4401 patients had undergone randomization, with a median follow-up of 2.62 years. The relative risk of the primary outcome was 30% lower in the canagliflozin group than in the placebo group, with event rates of 43.2 and 61.2 per 1000 patient-years, respectively (hazard ratio, 0.70; 95% confidence interval [CI], 0.59 to 0.82; P=0.00001). The relative risk of the renal-specific composite of end-stage kidney disease, a doubling of the creatinine level, or death from renal causes was lower by 34% (hazard ratio, 0.66; 95% CI, 0.53 to 0.81; P<0.001), and the relative risk of end-stage kidney disease was lower by 32% (hazard ratio, 0.68; 95% CI, 0.54 to 0.86; P=0.002). The canagliflozin group also had a lower risk of cardiovascular death, myocardial infarction, or stroke (hazard ratio, 0.80; 95% CI, 0.67 to 0.95; P=0.01) and hospitalization for heart failure (hazard ratio, 0.61; 95% CI, 0.47 to 0.80; P<0.001). There were no significant differences in rates of amputation or fracture. CONCLUSIONS In patients with type 2 diabetes and kidney disease, the risk of kidney failure and cardiovascular events was lower in the canagliflozin group than in the placebo group at a median follow-up of 2.62 years
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