An experimental investigation of the flow past a finite circular cylinder at a low subcritical Reynolds number

Results of hot wire measurements made in the near wake at a Reynolds number of 9955 are reported. The measurements include the mean velocity profiles, root mean square values of the velocity fluctuations, frequency spectra, and velocity cross correlations. The mean velocity profiles were used to determine the wake width, whose variation in the downstream and spanwise directions was examined. It is observed that close to the cylinder, the wake is narrower toward the free end than it is away from it, while further downstream the wake is wider toward the tip than it is away from it. It is found that the flow over the span can be characterized by four regions: a tip region where vortex shedding occurs at a lower frequency than that prevalent for away from the tip; an intermediate region adjacent to the first one where a frequency component of a nonshedding character is present; a third region characterized by a gradually increasing shedding frequency with increasing distance from the tip; and a two dimensional region where the shedding frequency is constant

Sampling Technique and Minimization of Inspection Errors in Leather Sorting

         Leather processing is one of the oldest industries. It involves processing of animals skins and hides for use in various products. The objectives of this study were to adopt a Sampling Plan Technique by comparison of various Sampling Plans in order to identify the best to be used in inspection process. This is to overcome human fatigue, to minimize the inspection time and to draw the Operating Characteristic Curve. A lot of 18000 pieces of wet blue goat skins for export was inspected for quality assurance to the standard quality level. These were set to be 10% & 5% for acceptable and rejects level by the supplier and customer respectively. Then various Acceptance Sampling Plans were compared then the probability of acceptance for lot quality level was evaluated using Operating Characteristic Curve. The results Showed that for quality assurance the best plan was when the lot size (N) was equal to  18000, the sample size (n) was equal to 350 and number of defects (c) was equal to 10. It is recommended that Acceptance Sampling Plan technique can be adopted by all Sudanese tanneries and related fields.           &nbsp

Application of Process Quality Control in Leather Industry

Quality Control is the regulatory process measuring actual quality performance, comparing it with standards, and rectifying the difference. The objective of this study was to design control charts for raw and export goat skins to ensure that non-defective items are used, and to ensure that defective items are not passed to customers. Ten random samples of raw goat skins of different sizes (32 – 125pieces) were taken and inspected, and then a control chart was drawn. For outgoing wet blue goat skin, ten samples of the same size each of (125pieces) were taken and inspected then a control chart was drawn. The results were as follow; the process involved in delivery of raw skins was out of control, because the proportion defective (0.2080) in one of the samples was located above the upper action limit. The process of outgoing skin showed stability on control chart because all samples were within control limits

Validation of a new method for building a three-dimensional physical model of the skull and dentition

We present a new method for replicating the skull and occlusal surface with an accurate physical model that could be used for planning orthognathic surgery. The investigation was made on 6 human skulls, and a polyvinyl splint was fabricated on the dental cast of the maxillary dentition in each case. A cone beam computed tomogram (CBCT) was taken of each skull and a three-dimensional replica produced. The distorted dentition (as a result of magnification errors and streak artefacts) was removed from the three-dimensional model and replaced by new plaster dentition that was fabricated using the polyvinyl splint and a transfer jig replication technique. To verify the accuracy of the method the human skulls and the three dimensional replica model, with the new plaster dentition in situ, were scanned using a laser scanner. The three-dimensional images produced were superimposed to identify the errors associated with the replacement of the distorted occlusal surface with the new plaster dentition. The overall mean error was 0.72 and SD was (0.26) mm. The accuracy of the method encouraged us to use it clinically in a case of pronounced facial asymmetry

Verification of calculation code THERM in accordance with BS EN ISO 10077-2

Calculation codes are useful in predicting the heat transfer features in the fenestration industry. THERM is a finite element analysis based code, which can be used to compute thermal transmittance of windows, doors and shutters. It is important to verify results of THERM as per BS EN ISO 10077-2 to meet the compliance requirements. In this report, two-dimensional thermal conductance parameters were computed. Three versions of THERM, 5.2, 6.3 and 7.1, were used at two successive finite element mesh densities to assess their comparability. The results were all compliant with the aforementioned British Standard

Mechanistic Insights on the Controlled Switch from Oligomerization to Polymerization of 1-Hexene Catalyzed by an NHC-Zirconium Complex

The benzimidazolylidene zirconium complex 1 switches from an oligomerization (without additive) to a polymerization catalyst by addition of an L-type ligand such as trimethylphosphine, while larger phosphines or amines completely inhibit catalysis. On the basis of the regioselectivity of the oligomers/polymers obtained, the time profiles of reactions as a function of added ligand, and the molecular structures of several cationic zirconium complexes, we propose a mechanistic framework for interpreting this complex catalytic behavior

Genetic and Multilocation Evaluation of High Yielding Provenances of Bhimal (\u3cem\u3eGrewia optiva\u3c/em\u3e) on Farmers’ Fields in North Western Himalayas

Agroforestry is the inclusion of woody perennial within farming systems, has been practiced as a traditional land use and livelihood option since time immemorial (FSI 2013). It is being practiced on agricultural lands for fuel wood and fodder (Khybri et al., 1992), as well as medicinal and fruit trees (Bijalwan, 2011; Rathore et al., 2014) enabling food security (Narain 1998), non timber forest products, timber and shelter etc. A number of different (185) agroforestry systems are popular among farmers in different agro-climatic regions (Solanki, 2006). Grewia optiva Drummond (Bhimal) is an important agroforestry tree species primarily grown for green fodder in the north west Himalayas (Khybri et al., 1992; Dhyani, 2009). It is distributed throughout the sub-Himalayan tract upto an altitude of 1800m. Therefore, the present study was envisaged to monitor the performance of three best provenances of Bhimal (Mehta et al., 2011) on farmers’ fields at four locations comprising middle hill elevations and valley zones and their effect on field crops

Concurrent Acquisition of a Single Nucleotide Polymorphism in Diverse Influenza H5N1 Clade 2.2 Sub-clades

Highly pathogenic Influenza A H5N1 was first identified in Guangdong Province in 1996, followed by human cases in Hong Kong in 1997. The number of confirmed human cases now exceeds 300, and the associated Case Fatality Rate exceeds 60%. The genetic diversity of the serotype continues to increase. Four distinct clades or sub-clades have been linked to human cases. The gradual genetic changes identified in the sub-clades have been attributed to copy errors by viral encoded polymerases that lack an editing function, thereby resulting in antigenic drift. We report here the concurrent acquisition of the same polymorphism by multiple, genetically distinct, clade 2.2 sub-clades in Egypt, Russia, and Ghana. These changes are not easily explained by the current theory of “random mutation” through copy error, and are more easily explained by recombination with a common source. This conclusion is supported by additional polymorphisms shared by clade 2.2 isolates in Egypt and Germany