FDM preparation of bio-compatible UHMWPE polymer for artificial implant

Due to its properties of high wear, creep resistance, high stiffness and strength, Ultra-High Molecular Weight Polyethylene (UHMWPE) was developed to eliminate most metallic wear in artificial implant, which conventionally found in stainless steel, Cobalt Chromium (Co-Cr) and Titanium (Ti) alloys. UHMWPE has an ultra-high viscosity that renders continuous melt-state processes including one of the additive manufacturing processes, Fused Deposition Modeling (FDM) ineffective for making UHMWPE implant. Attempt to overcome this problem and adapting this material to FDM is by blending UHMWPE with other polyethylene including High Density Polyethylene (HDPE) and Polyethylene-Glycol (PEG) which provide adequate mechanical properties for biomedical application along with the improvement in extrudability. It was demonstrated that the inclusion of 60% HDPE fraction has improved the flowability of UHMWPE in MFI test and showing adequate thermal stability in TGA

High magnetoresistance at room temperature in p-i-n graphene nanoribbons due to band-to-band tunneling effects

A large magnetoresistance effect is obtained at room-temperature by using p-i-n armchair-graphene-nanoribbon (GNR) heterostructures. The key advantage is the virtual elimination of thermal currents due to the presence of band gaps in the contacts. The current at B=0T is greatly decreased while the current at B>0T is relatively large due to the band-to-band tunneling effects, resulting in a high magnetoresistance ratio, even at room-temperature. Moreover, we explore the effects of edge-roughness, length, and width of GNR channels on device performance. An increase in edge-roughness and channel length enhances the magnetoresistance ratio while increased channel width can reduce the operating bias.Comment: http://dx.doi.org/10.1063/1.362445

Thaan Vuzha Nilam Tharisu: the land without a farmer becomes barren

This report forms a part of the international research project on policy and sustainable agriculture, Policies that Work for Sustainable Agriculture and Regenerated Rural Economies. The report details the findings of one of the constituent studies, undertaken by an Indian NGO, the Society for People's Education and Economic Change (SPEECH). The Importance of this project is that it concentrated on rainfed rather than irrigated agriculture - i.e. the sharp end of rural development in India, and that the focus was very much on the micro-level, looking at policy as seen from the ground. One of the recurring themes throughout the research was the importance of appreciating people as individuals, and in this spirit some of the personal qualities of the research team are shared. The research covers events in sites in the Virudhunagar district of Tamilnadu: Tiruchuli Panchayat Union and the Villur chain of tanks. This is an essentially rural area, where the need for sustainable forms of agriculture and rural livelihoods is clear. The political landscape is fractured and complex (§2.3), and the officials with the responsibility of implementing policy face significant obstacles and disincentives in doing so in response to the needs of local communities

On the apllication of single specie dynamic population model

The Method of mathematical models of Malthus and Verhults were applied on ten years data collected from Magaram Poultry Farm to determine the nature of population growth, population decay or constant growth in a Poultry Farm, and independent t-test as well as one way Anova  were used to compare the predicted values and observed values in order to find out whether there is significant difference between the observed and predicted values using these two models.Keywords: Birth rate, sustainable population, overcrowding, harvesting, independent t-test and one way Anova

Effects of Thickening Time on the Application of Cement Slurry for High Pressure /High Temperature Drilling.

High pressure/High temperature operations remain a high challenge for the industry as deeper reservoir operations are pursued around the globe. In addition to deeper depths, an increasing number of wells are still being drilled and completed in much more hostile down-hole environments. Though high pressure/high temperature wells have always presented drilling challenges, their operations continued to remain very high as the vast reserves of hydrocarbon promised to bridge the gap between demand and supply for energy. The world’s energy demand is rising and favorable economics have allowed oil companies to continue to prospect and drill in these more challenging areas that are actually prone to high pressures / high temperatures than ever before. This paper addresses some of the challenges relative to cement slurry designs that requires careful engineering practices and needs proper cementing operations and optimization. It presents a simulation study using retarder sensitivity to select thickening time, optimize cement properties and also predict the subsequent HPHT sensitivity on cement slurries. The results showed that the modified Magnesium Oxide(mixture of water-glass and magnesium oxide) was best for slurry design for high pressure/high temperature which gave tighter matrix of cement paste. The application of retarder reduced the thickening time but the Water-Glass Solution improved the Magnesium Oxide cement thickening time, indicating that thickening time was dependent on time of exposure and on temperature. The rheological properties of the slurry showed that at HPHT, there were decreases in plastic viscosity, gel strength and the yield point. The study therefore determined one of the best cement slurry design practices for different down-hole applications in HPHT wells. KEY WORDS : Cement slurry, Thickening Time, Modified magnium Oxide,High temperature/High Pressure

Evaluation of Preoperative Hair Removal and its Relationship with Postoperative Wound Infection at a Tertiary Health Facility in North-eastern Nigeria

BACKGROUND: The general surgery unit of Federal Teaching Hospital Gombe performs several surgeries via the hair bearing areas. A pilot study by the unit on the incidence of SSI for all clean surgeries showed an alarming forty- six percent. (38) The reported infection rate for such infection is <2% by CDC standard. This study was done to probe the role of preoperative hair removal in such high infection rate. OBJECTIVES: the study aimed to determine the relative postoperative wound infection rates of Razor blade shaving and cream depilation.  It also assessed the adequacy of hair removal by both methods and the type of skin injuries or reactions that follow each method METHODS: a prospective, cross-sectional, double-blinded study was done between July 1st to December 31st 2016 on 98 patients that met the inclusion criteria and randomized by balloting. BIC shaving stick produced by BIC SOCIETE, FRANCE and VEETO CREAM(thioglycollate) produced by RECKIT BENCKISER, were used for preoperative hair removal. Adequacy of hair removal, post shaving skin injuries and reactions were assessed preoperatively by research assistants. Post-operative wounds were graded using the Southampton wound scoring system for SSI. Data obtained was analyzed with SPSS software version 20.0 and statistical relationships were assessed using Chi-square. RESULTS: a total of 98 patients were recruited for the study. 53(54.1%) were males and 45(45.9%) were females. The mean age was 45.99(+ 12.522) with a range of 16-76 years. Majority (88.8%) had open repair of abdominal wall hernia, followed by Scalp lipoma (6.1%), groin lipoma (3.1%) scalp osteoma and superficial Parotidectomy (1%) each. 57(58.2%) had razor blade shaving and 41(41.8%) had cream depilation. 91(92.9%) had adequate hair removal considering both methods. Depilatory cream use is however, more effective, with (97.6%) adequacy. Razor blade shaving recorded (89.5%) adequacy. Out of the patients, only 4(4.1%) had skin injuries and all are in the razor blade group. Depilatory cream use caused more skin reactions (7.3%) compared to razor blade use (1.8%). 6(6.1%) of all the patients developed SSI and 5(83.3%) (x2 1.6662) are in the razor blade group. Majority of the postoperative wounds (83.3%) are Southampton class A &B. 16.7% is class C  CONCLUSION: preoperative hair removal using razor blade or cream depilation is associated with postoperative wound infection (6.1%). Razor blade shaving is how ever more prone to postoperative wound infection, although, the difference in the infection rate is not statistically significant (p-value 0.197). Preoperative cream depilation is more efficient and safer. LIMITATIONS: The sample size is rather small, as only patients presenting at the general surgery unit were recruited. This limited the scope of subjects that were    assessed, as other units in the surgery department also operate in hair bearing areas. Multiple nurses were involved in the razor blade shaving and cream application, inter-personal differences in technique may affect the outcome in terms of skin injury. Subjective method of direct visual assessment of skin injury was resulting in missing non obvious skin injuries. The use of electron viewing microscope would have improved the discovery of such injuries

Radiation detectors for nuclear well-logging application: A review

The oil and gas industry uses nuclear logging method to survey for the presence of hydrocarbons in a given region of interest. Nuclear logging tools are used to achieve this aim. These tools consist of radiation sources and radiation detectors. 3He thermal neutron detector and NaI:Tl for gamma-ray measurements are the conventional detectors used for this application. However, the shortage of 3He gas used in 3He tube and the high demand for both detectors in many other societal applications has mandated the search for alternative radiation detectors. This paper reviewed other alternatives that are commercially available. Light output, temperature sensitivity, tolerance to vibration and shock are important parameters to consider when selecting a detector for this application. Among the reviewed alternatives, GS20 crystal for neutron and gamma ray measurements, LaBr:Ce and LuYAP:Ce for gamma ray measurement have been reported to have comparable performance to the conventional detectors

Vegetation indices mapping for Bhiwani district of Haryana (India) through LANDSAT-7ETM+ and remote sensing techniques

This study describes the VIs Vegetation Condition Index in term of vegetation health of wheat crop; with help of LANDSAT-7ETM+ data based NDVI and LAI for Bhiwani District of Haryana states (India) and gave the spatial development pattern of wheat crop in year 2005 over the study area of India. NDVI is found to vary from 0.3 to 0.8. In northern and southern parts of study area NDVI varied from 0.6 to 0.7 but in western part of Bhiwani showed NDVI 0.2 to 0.4 due to fertility of soil and well canal destitution. LAI showed variation from 1 to 6 accordingto the health of crop as the same manner of NDVI because LAI VI is NDVI dependent only change the manner of representation of vegetation health, due to this fact relation curve (r2=) between NDVI and LAI of four different growing date of sates are in successively increasing order 0.509, 0.563, 0.577 and 0.719. The study reveals that VIs can be mapped with LANDSAT-7ETM+ through remote sensing, which can be further used for many studies like crop yield or estimating evaptranspiration on regional basis for water management because satellite observations provide better spatial and temporal coverage, the VIs based system will provide efficient tools for monitoring health of crop for improvement of agricultural planning. VIs based monitoring will serve as a prototype in the other parts of the world where ground observations are limited or not available