Evaluation of Mechanical Properties of Damascus Steel

This article deals with examination of the mechanical properties of Damascus steel. Damascus steel is steel used for blades or knives – similar to the past (Damascus steel was a type of steel used for blades in the Near East – made from wootz steel – imported from India). This steel is characterized by significant patterns. The aim of the present study is to point out the laborious method of Damascus production, and to compare the mechanical properties of the initial Damascus steel layers comparison with whole reference Damascus material steel itself.

EVALUATION OF THE CONTACT SURFACE PARAMETERS AT KNURLING FINNED HEAT-EXCHANGING SURFACE BY KNURLS AT RING BLANKS

Tubular parts with an external finned heat-exchanging surface are usually produced by the laborious method of cutting on lathes. Besides, there is a method for the high-performance manufacturing of fins by cold knurling with ring-cut knurls, which, compared with cutting, reduces labor intensity by two to six times with a significant increase in the operational properties of the product. The disadvantage of the cold knurling method with ring-cut knurls can be unwanted surface defects and deformations of the entire product. Obtaining finned surfaces on ring blanks with high surface quality during knurling requires accurate calculation of the ratio of longitudinal and transverse strains. The most important factors determining the ratio of longitudinal and transverse strains (rolling-out and rolling-off) are the length and width of the contact surface. The need for a quantitative assessment of the parameters of longitudinal and transverse strains determined the purpose of this manuscript. This study aimed to develop a methodology for calculating the contact surface of a knurl with a ring blank (pipe) when knurling with ring-cut knurls. The proposed method for calculating the knurl's contact surface with a tube when knurling with ring-cut knurls allows for estimating the recommended range of pipe sizes for knurling. Based on the dependencies mentioned in the manuscript, the limiting sizes for blank pipes were calculated to ensure high-quality finning. Experiments on cold rolling of ribbing on pipes with different lengths and diameter ratios were carried out, confirming the possibility of using the proposed methodology for calculating the knurl's contact surface with a pipe when knurling heat-exchanging finning with ring-cut knurls.

Systematic Medication Review in General Practice by an Interdisciplinary Team: A thorough but Laborious Method to Address Polypharmacy among Elderly Patients

Polypharmacy increases the risk of hospitalization but may be reduced by medication review. The study objective is to describe and evaluate a method for conducting medication review in general practice by an interdisciplinary medication team of pharmacists and physicians—in this case conducted by a team from the Department of Clinical Pharmacology—based on information concerning medication, diagnosis, relevant laboratory data and medical history supplied by the general practitioner. We discussed the medication review with the patients’ general practitioners and received feedback from them regarding acceptance rates of the recommended changes. Ninety-four patients with a total of 1471 prescriptions were included. A medication change was recommended for nearly half of the prescriptions (48%); at least one change of medication was recommended for all patients. The acceptance rate for recommended medication changes was 55%, corresponding to a mean of 4.2 accepted recommendations per patient. For 18% of all 1471 prescriptions, the general practitioner agreed either to discontinue (stop the medication completely) or reduce the dose of the medication. This method is thorough, but since it requires several healthcare professionals, it is rather time-consuming. There is a need to support medication review in general practice, but although this method may be too time consuming in most cases, it may nevertheless prove to be a useful tool managing the most complicated patients.

DNA extraction from resin producing Boswellia tree

The wild nature of plant and the presence of the secondary compounds e.g., Resin and phenolic compound make DNA extraction problematic. Some of them will co-precipitate with DNA during extraction and inhibit further enzymatic modification of the DNA. Furthermore large amounts of complex polysaccharides also make extraction of usable DNA impossible. Previously reported protocols yielded highly viscous and slimy DNA preparations that were not amenable to further analysis. We tried many commonly used protocols but were unable to isolate high quality DNA from the gum containing plant Bosweliia sacra. We did extensive optimization of the Cetyl Trimethyl Ammonium Bromide \(CTAB) protocol established by Doyle in 1987 to extract DNA which is feasible for PCR amplification. In this study, we have specifically tested the previously developed CTAB based protocols developed by I Haque adapted for Commiphora wightii and Bipin Deochand Lade protocol developed for Passiflora foetida. Both are developed for plants, which contain high amount of secondary metabolites, polysaccharides and phenolic compounds. Furthermore, we investigate the possibility to extract DNA from resin producing plants which is feasible for downstream application. To our knowledge, this is the first optimized protocol which a rapid and less laborious method for the extraction of DNA from Boswellia species \(Boswellia sacra and Boswellia elongata found in Oman and Yemen respectively) which are resin \(Luban) producing plant. The isolated DNA by the currently optimized protocol were suitable for polymerase chain reaction \(PCR) mediated amplification for applications genetic diversity and DNA barcoding.

Validation of a simple method for the interpretation of uterine cytology in cows

One of the main drawbacks of using endometrial cytology in cows is the time required for sample collection and interpretation. It is recommended to count a large number of polymorphonuclear neutrophils (PMN) and to calculate their overall percentage. However, since counting a large number of cells is a laborious method, it would be preferable to simplify the analysis by counting the number of PMN in few microscopic fields. Therefore, the aim of this study was to assess whether a simple test, based on calculating the average number of PMN in 10 fields at 1000×, could be a reliable technique for the diagnosis of endometritis. Two hundred and sixty endometrial samples were taken from Holstein cows at different postpartum stages using an adapted cytobrush. Smears obtained were air-dried for fixing and stained with a Romanowsky-type procedure. To evaluate the counting method, the percentage of PMN in 150 cells was calculated as well as the average number of PMN in 10 fields at 1000×. Receiver operating characteristic (ROC) curves was constructed to evaluate both methods, the percentage of PMN (used as reference) and the average number of PMN. It was observed that the area under the curve is (regardless of cut-off used) higher than 0.99 and the correspondence between both methods were 1.58 PMN/field for the cut-off value of 15% and 2.40 PMN/field for the cut-off value of 20%. These results show that this simple method could be used to determine the percentage of PMN in endometrial cytological samples and to diagnose endometritis in cows.

A COMPARISON OF COMPUTERIZED IMAGE ANALYSIS AND STEREOLOGY AS TOOLS FOR MORPHOLOGICAL STUDY OF ALGAL CELLS

A computerized image analysis package (ImagePro+) was evaluated as an alternative method for morphometric analysis of electron micrographs of microalgal cells. The morphometric analysis was demonstrated with micrographs of the marine alga Nannochloropsis sp. grown under high and low light intensity. We applied the ImagePro+ package to estimate the relative volume of an organelle based on the ratio of perimeters of the organelle and the cell. The measurements included the volumes of chloroplasts, mitochondria, nuclei, vacuoles, and accumulation bodies, all relative to cell volume. The length of thylakoids was measured using the same package. The results obtained by ImagePro+ were compared to those of the traditional manual and laborious method involving the superimposition of an array of short lines on the micrograph. A high correlation between the methods was found. The following correlations were found for chloroplast, nucleus, and accumulation bodies: 0.96, 0.92, and 0.75, respectively. The correlation between length of thylakoids (ImagePro+) and surface area of thylakoids (superimposition) was 0.82.

Temperature-sensitive mutants ofPhysarum polycephalum– expression of mutations in amoebae and plasmodia

SUMMARYOver 100 temperature-sensitive mutants ofmt-h (apogamic) strains ofPhysarum polycephalumwere isolated either by testing clones of mutagenized amoebae (ATS mutants) or by the more laborious method of testing plasmodia derived from such clones (PTS mutants). When amoebae and plasmodia of each mutant were tested for growth temperature sensitivity on different media (to give optimum growth of each phase), only 21% of 73 ATS mutants and 32% of 31 PTS mutants appeared to be temperature-sensitive in both phases, suggesting that the majority of mutants are phase-specific, as concluded from several similar studies by previous authors. When the mutants were tested on a third medium which allows growth of both amoebae and plasmodia, many of the mutants no longer had a temperature-sensitive phenotype in either phase. Among the remainder, 51% of ATS mutants and 67% of PTS mutants were temperature-sensitive in both phases. It was suggested that certain media have a remedial effect on some temperature-sensitive mutants so that the phenotype is apparently normal. Thus, the proportion of phase-specific mutants may be over-estimated if tests of temperature-sensitivity are done on the different media commonly used for culture of amoebae and plasmodia respectively. It was concluded that the most efficient procedure for isolation of temperature-sensitive mutants expressed in plasmodia is to screen clones of amoebae on a medium resembling as closely as possible that which is to be used for testing plasmodia.

An analytical representation of the geomagnetic field in Canada for 1975. Part I: The main field

Approximately 51 000 observations made between 1955 and 1973 were used to produce the magnetic charts of Canada for 1975. A least-square method was used to derive sixth degree polynominals for the rectangular components X(north), Y(east), and Z(vertical). Cubic time terms were included to eliminate the customary laborious method of updating the data to the desired epoch.To reflect desired wavelengths of approximately 1000 km it was necessary to divide the map area of 31 × 106 km2 into quadrants with a unifying overlap of 10%. For consistency, X and Y were analysed together using Maxwell's curl-free relation (curl F)Z = 0. All data were weighted according to type and age.From the derived polynomials, values of D (magnetic declination), H (horizontal intensity), and Z were computed at 2° geographic grid intervals. These values were used to derive the final charts using a standard contouring package.The overall root mean square (rms) fit of the model to the input data is 174 nT. In the auroral zone, an area of high magnetic activity, the fit is generally poor. The fit to over 8500 supplementary observations is 170 nT, confirming the reliability of the model.

Fertilizer Placement for Sole-Crop Cowpeas in Southern Nigeria

SummaryThe time and method of placement, and the distance from the plant at which fertilizers should be placed, was studied on sole-crop cowpeas. The development and yield of both early and late season crops were highest where fertilizers were applied at planting. It is suggested that it might be more advantageous to plough the fertilizers under before planting, so that the nutrients will become available to the seedlings from the time they emerge. Application of fertilizer in two bands gave the highest yields, but was not significantly superior to a less laborious method of application in one band. The distance at which the fertilizer was placed, and treatment interactions, did not show any definite trends.