Volume-8, Issue-5, May 2022

Abstract

The development of the manufacturing process to fabricate miniaturized components goes through aspects such as modifications of machines and tools, process optimizations, improvements in precision and accuracy, and fabrication of adapted geometries. Hot-embossing, laser abrasion, and microinjection molding are applicable methods of fabrication to a diversity of geometries and polymeric materials. Rapid prototyping and fabrication assist in the development of new products in a short amount of time with a reduction in costs, allowing the manufacturing of objects with tenths of millimeters and with an accuracy in the order of micrometers. 3D Printing process with photocurable resin is a recent method of rapid prototyping that is growing in the market. Intending to analyze how precise and accurate is the process of 3D printing of miniaturized models and analyze their dimensional tolerance, it was conducted a dimensional analysis of parts fabricated in a printer EDEN 250 by Objet. Qualitative results showed that EDEN 250 prints satisfactory small parts mainly with round formats. Parts with sharp edges show limitations regarding precision and accuracy. FullCure ® 720 is a resin with average quality since it absorbed moisture and is heat sensitive. Studied samples were classified according to the technical standard NBR 6158 as IT11 parts (max tolerance of ± 60 μm).

Keywords: Rapid prototyping, 3D Printing, dimensional precision and accuracy

References

Keywords: Rapid prototyping, 3D Printing, dimensional precision and accuracy

Abstract

Background: To establish the trimester-specific reference intervals of thyrotropin (TSH), free thyroxine (FT4) and free triiodothyronine (FT3) in healthy pregnant women in Macau.

Methods: Serum samples were collected from 166 healthy pregnant Macau women since early pregnancy until the third trimester. The study was performed in Macau Kiang Wu Hospital from July 2020 to October 2021.Basic clinical and obstetrics data were gathered using questionnaires. Blood samples were sequentially collected from the pregnant women at the first (≤12weeks), the second (12-28 weeks) and the third (>28 weeks) trimesters, respectively.

 Result: Reference intervals of TSH were 0.02~3.30mIU/L, 0.45~3.80mIU/L and 0.18~3.43mIU/L in three trimesters. For FT4, Reference intervals were 12.82~22.0pmol/L, 9.86~15.58pmol/L and 10.10~15.30pmol/L in three trimesters. For FT3, Reference intervals were 3.53~6.0pmol/L, 2.74~4.65pmol/L and 2.62~4.45pmol/L in three trimesters. The concentration of TSH was significant lower in the first trimester compared to the second and third trimesters of pregnancy (median o.89, 1.66, 1.41mIU/L); TSH concentration differences between trimesters are significantly different (p<0.05).FT4 values decreased with the progression of gestational period (median 16.60, 12.40, 12.15pmol/L). FT3 values decreased with the progression of gestational period (median 4.56, 3.65, 3.57pmol/L). FT4 and FT3 concentration had significantly differences between first and second trimesters (p<0.05), but had no significantly differences between second and third trimester (p>0.05).

 Conclusion: This study is the first to establish trimester-specific reference intervals of TSH, FT4 and FT3 in healthy pregnant Macau women. Trimester-specific reference intervals may help in diagnosis and management of thyroid dysfunction during pregnancy which will prevent both maternal and fetal outcomes.

Keywords: pregnancy, reference-intervals, thyroid hormone.

References

Keywords: pregnancy, reference-intervals, thyroid hormone.

Abstract

When a seismic event causes unwanted motion in buildings, energy dissipation techniques in civil engineering are required. There are a variety of structures with passive energy dissipation provided by Passive Constant friction damper systems (CFRD). This technique is being used more and more to increase seismic protection for both existing and new constructions. The CFRD system results are explored in order to compare the structural response with and without this device of energy dissipation compared for low and high rise mass varied buildings, the damper put at different storey and altering the slip force has been focused in this study which gives an insight into the variation of slip load and its locations. The CFRD's potential to boost the structure's dissipative capacities without increasing stiffness was discovered. In the case of high-rise buildings, CFRD performance has been examined using top-storey displacements, allowing for a conclusion.

Keywords: Constant Friction Damper, High Rise Buildings, Seismic Response, Slip load, Tall Structures.

References

Keywords: Constant Friction Damper, High Rise Buildings, Seismic Response, Slip load, Tall Structures.

Abstract

The chloro compound, Ethene, Amine, Carbonyl compound, cyanide and methylene compounds were assigned 889.9796 cm-1 , 1401.735 cm-1 , 1627.371 cm-1 , 2208.360 cm-1 , 2445.666 cm-1 and 2600.767 cm-1 respectively. Methylene has a weak band, making it less prominent in Bull’s bloodmeal. The fresh blood and dried blood of a red Bororo male cattle was subjected to infra-red spectroscopy at Spring board laboratory, Awka, Anambra State, Nigeria. The interactive effects due to the functional groups during drying were responsible for the changes observed in the spectra. It can be deduced that the dried sample has a more stable and sharper bands than those of the fresh sample. The infra-red spectrum of the bloodmeal consists of several peaks. At the region of N-H stretches, the peak looks like a cow udder, confirming the presence of primary amine.

Keywords: Blood, Bloodmeal, Amine, Amino acid, Protein, Functional group, Peak.

References

Keywords: Blood, Bloodmeal, Amine, Amino acid, Protein, Functional group, Peak.

Abstract

To date, there is no easy-to-use method and device for its implementation for the detection of codivirusinfectious people by exhalation. The main method of covid infection is airborne when droplets of the infected saliva person enter the oral cavity of healthy person. Such method would make it possible to detect infected people and prevent them from entering in public places and send them to quarantine immediately. The method is not traumatic, unlike the PCR test, and along with other methods, it would allow adjusting the patients covid treatment in the hospital. Currently, gas analyzers are accurate research methods with a division value of 1 ppm. The purpose of this work is to identify which gases during the exhalation of infected or sick person are decisive, how to measure them during exhalation, how these gases are associated with entry proteins and enzymes of saliva? How change a gas concentrations depending from the infection and illness time, and what are their values?

Keywords: codivirus-infectious people by exhalation, gas analyzers

References

Keywords: codivirus-infectious people by exhalation, gas analyzers

Abstract

This study sought to establish optimum techno-economic replacement policies for the transmission unit of locally-fabricated oil palm fruit digester for cost-effective operation over a planning horizon of sixteen years. Deterministic Dynamic programming models were used in the study. The companies whose records were most amenable to the model’s application were used as as cases for the study. The records were painstakingly collated and processed for deployment in the models. The depreciation, cost of operation and maintenance, and the Equivalent Uniform Annual Cost (EUAC) of the unit were evaluated. The equipment EUAC is evaluated over all the periods of the planning horizon. The period with the lowest EUAC is recommended by the model as the most cost-effective replacement period. The companies’ replacement practice was assessed for its conformity with the replacement policy predicted by the model in a kind auditing approach. The companies were shown to incur increased EUAC for retaining the transmission unit beyond the replacement age recommended by the models. Deployment of replacement models for machinery replacement decisions support can enhance an industry’s economic advantage in today’s competitive industrial environment.

Keywords: Oil palm fruit digesters, Dynamic programming models, Equipment replacement age, Equipment economic life, Replacement practice audit and Equivalent uniform annual cost.

References

Keywords: Oil palm fruit digesters, Dynamic programming models, Equipment replacement age, Equipment economic life, Replacement practice audit and Equivalent uniform annual cost.

Abstract

This article deals with the effects of a temperature, pressure, gravity, pipe flanges and saddle supports of a measurement section of the pipeline on changes in the pipe geometry. The investigation was aimed, in particular, at examining changes in diameters of two pipeline sections relative to changes in their internal pressure, which ranged from 0 MPa to 6.0 MPa, and to changes in temperature, which ranged from 0 °C to 25 °C. As indicated by the results of a numerical simulation carried out within this research, a change in a diameter can be expressed most accurately if the effects of gravity, saddle supports and flanges are neglected. Changes in pipe diameters were examined merely as a function of changes in pressure and temperature. Gravity, flanges and saddle supports cause irregular pipe deformities that occur along the pipe circumference and length. These effects prevented identification of real values of changes in the pipe diameter on the measurement sections of the pipeline.

Keywords: measurement pipe section, saddle supports, flanges, gravity

References

Keywords: measurement pipe section, saddle supports, flanges, gravity