Simulation and analysis of vibration signals generated by rolling element bearing with defects

Dynamic loading of a rolling element bearing structure is modeled by a computer program developed in Visual Basic programming language. The vibration response of the structure to the dynamic loading is obtained using a standard finite element package I-DEAS. A force model is proposed to model the localized rolling element bearing defects. Time and frequency domain analyses are performed for diagnostics of rolling element bearing structures. Statistical properties of the vibration signals for healthy and defected structures are compared. The envelope (HFRT) method is employed in the frequency domain analysis. The effect of the rotational speed on the diagnostics of rolling element bearing defects is investigated. An optimum sensor location on the structure is sought. Effect of the structure geometry on the monitoring techniques is studied. An optimum monitoring method can be employed by analyzing the rolling element bearing structure following the procedure proposed in this study. The present commercial computer aided engineering packages can be used in special engineering applications such as condition monitoring of rolling element bearings.     

Classification of Drinking Water Quality Index and Identification of Significant Factors

Water pipes are considered to be one of responsible sources for the water pollution. Among these sources of water supply, the water pipes are the only source of carrying out fresh or processed water into lakes, ponds and streams etc. In Pakistan, knowledge on the condition of water pipes is scarce as deterioration of water pipes are hardly inspected due to high cost. The aim of the current research was to examine the quality of water pipelines of eight districts of South-Punjab, namely, Mianwali, Khushab, Layyah, Bhakkar, Dera Ghazi Khan, Muzaffargarh, Rajanpur and Rahim Yar Khan. Selected sampling stations were analyzed for physio-chemical parameters such as pH, Total Dissolve Solids (TDS), Sulfate (SO₄), Chlorine (Cl), Calcium (Ca), Magnesium (Mg), Hardness, Nitrate (NO₃), Fluoride (F) and Iron (Fe). The data pertaining water monitoring contain different parameters and seem difficult work for the interpretation of water quality by managing different parameters separately. For this purpose, National Sanitation Foundation Water Quality Index (NSF-WQI) was determined to communicate the quality of water in a simple form. Besides this, groups comprising of similar sampling sites based on water quality characteristics were identified using unsupervised technique. Factor Analysis (FA) has been performed for extracting the latent pollution sources that may cause the more variance in large and complex data. The calculated values of WQI from 1600 sampling stations ranging from 20.73 to 223.74 are divided into five groups; Excellent to Unsuitable class of waters with the average value 62.09 described as good limit for drinking water. Further sampling stations are divided into five optimal clusters selected with suitable k value obtained from Silhouette coefficient. Results of k-means clustering are also verified with natural groups made by WQI. Analysis of multivariate techniques showed several factors to be responsible for the water quality deterioration. It is found out from the FA that three latent factors such as organic pollution, agriculture run-off and urban land use caused 83.30 % of the total variation. Hence, water quality management and control of these latent factors are strongly recommended.     

An investigation into gamma-ray treatment of shellfish using electron paramagnetic resonance spectroscopy

BACKGROUND: Gamma irradiation is a safe method for the decontamination of shellfish, and its technical feasibility and safety have been endorsed (FAO/IAEA/WHO). In order to implement proper food‐processing regulations, the identification of radiation treatment is required. In this study, electron paramagnetic resonance (EPR) spectroscopy was employed to identify the irradiation of seven different types of commonly consumed shellfish. RESULTS: Characteristics (g factor and signal intensity) of the EPR spectra of control and irradiated samples were recorded in order to clarify the gamma‐ray treatment of shellfish. Radiation‐specific signals around g = 2.0038 ± 0.0006 (g₁) and g = 1.9996 ± 0.0002 (g₂ and g₃) were observed for all shellfish samples irradiated with absorbed doses of 3 and 6 kGy. The X‐ray diffraction (XRD) spectra of some shellfish samples were recorded to investigate their mineral profiles. CONCLUSION: The EPR spectroscopic results indicated that carbonate minerals were the source of the paramagnetic species that were produced upon irradiation, entrapped in the shellfish and showed radiation‐specific asymmetric signals whose intensities increased quantitatively with the absorbed radiation dose. The XRD analysis revealed that aragonite and calcite minerals were present in the shells of shellfish. Copyright © 2011 Society of Chemical Industry     

Optimal Agricultural Water Allocation for the Sustainable Development of Surface and Groundwater Resources

This paper presents a multiobjective linear program for the optimal allocation of water resources among various crops in a large canal command area of Pakistan. The available surface water in the canal cannot meet the net irrigation requirement (NIR) of various crops, which leads to the overexploitation of groundwater and causes salinity problems. Therefore, an optimal water allocation model was formulated using the simultaneous compromise constraint (SICCON) technique for the sustainable development of surface water and groundwater. Three (03) single objective functions (OFs) and a multiobjective function (MOF) were considered in this study. The MOF combines the single OFs by developing an arrangement among them to both maximize the satisfaction rate for surface water (SR_s) and net economic returns (NER) and minimize the salinity problems. The available surface water (AW) of 1531 Mm³ was allocated among various crops, i.e., wheat, cotton, sugarcane, rice, onion, and sunflower, using the SICCON technique, and the deficit was accounted for with groundwater reserves. The model results showed an average increase of 22% in SR_s and 7.2 million USD in NER_s from surface water allocation compared to the current water allocation practice. Moreover, the salinity levels of the allocated water exceed the threshold limits of onion, sugarcane, and rice crops in the current water allocation system and thereby negatively impact agricultural production. Hence, the model used in this study may support decision-makers in the optimal selection of different crops to be irrigated to maximize the SR_s and NER_s and minimize salinity problems.

     

Dietary mycotoxins binders: a strategy to reduce aflatoxin m1 residues and improve milk quality of lactating Beetal goats

Aflatoxin M1 (AFM1) is a metabolite of aflatoxin B1 (AFB1) and secreted in milk of animals that are kept on a moldy diet. AFB1 is produced by several toxigenic species of fungi. In this study, the comparative efficacy of two mycotoxin binders was evaluated in terms of reducing excretion of AFM1, total viable bacterial count and somatic cell count in milk obtained from goats fed with AFB1 contaminated diet. A total of 32 lactating Beetal goats were reared and divided into 4 equal groups: Animals of group A were kept as control, while those in groups B, C, and D were individually fed with AFB1 at 40 µg alone, 40 µg AFB1 along with mycotoxin binder Toxfin^® at 3 g kg^?1 of cotton seed cake, and 40 µg AFB1 along with mycotoxin binder Elitox^® at a dose rate of 1 g kg^?1 of cotton seed cake, respectively. Toxfin^® significantly decreased the excretion of AFM1 in goats’ milk by 49.57 % while Elitox^® non-significantly reduced the excretion of AFM1 in goats’ milk by 19.49 %. Total viable bacterial count in milk samples of group C and D, and somatic cell count in milk samples of group C did not reduce significantly. However, somatic cell count in milk samples of group D reduced significantly. We conclude that the addition of Toxfin^® in the moldy diet significantly reduce the excretion of AFM1 in animals’ milk and minimize the risk of mycotoxin toxicity to public health.     

Tea and Its Consumption: Benefits and Risks

The recent convention of introducing phytochemicals to support the immune system or combat diseases is a centuries’ old tradition. Nutritional support is an emerging advancement in the domain of diet-based therapies; tea and its constituents are one of the significant components of these strategies to maintain the health and reduce the risk of various malignancies. Tea is the most frequently consumed beverage worldwide, besides water. All the three most popular types of tea, green (unfermented), black (fully fermented), and oolong (semifermented), are manufactured from the leaves of the plant Camellia sinensis. Tea possesses significant antioxidative, anti-inflammatory, antimicrobial, anticarcinogenic, antihypertensive, neuroprotective, cholesterol-lowering, and thermogenic properties. Several research investigations, epidemiological studies, and meta-analyses suggest that tea and its bioactive polyphenolic constituents have numerous beneficial effects on health, including the prevention of many diseases, such as cancer, diabetes, arthritis, cardiovascular disease (CVD), stroke, genital warts, and obesity. Controversies regarding beneficialts and risks of tea consumption still exist but the limitless health-promoting benefits of tea outclass its few reported toxic effects. However, with significant rise in the scientific investigation of role of tea in human life, this review is intended to highlight the beneficial effects and risks associated with tea consumption.     

Effects of individual and combined administration of ochratoxin A and aflatoxin B1 in tissues and eggs of White Leghorn breeder hens

BACKGROUND: Mycotoxins, the secondary fungal metabolites, are unavoidable contaminants of human and animal food and feeds. The objectives of this study were to evaluate the effect of concurrent feeding of ochratoxin A (OTA) and aflatoxin B₁ (AFB₁) to breeder hens, upon their deposition in different tissues and eggs. RESULTS: Residues of OTA and AFB₁ in (ng g^?1) were significantly higher in liver followed by kidneys and breast muscles by 22.54 ± 1.48, 4.22 ± 0.93 and 0.56 ± 0.06 for OTA (group fed OTA at 5 mg kg^?1 diet) and 1.44 ± 0.21, 0.25 ± 0.01 and 0.03 ± 0.01 for AFB₁ (group fed AFB₁ at 5 mg kg^?1 diet), respectively. Residues of OTA and AFB₁ in eggs appeared at days 3 and 5 of toxin feeding and disappeared at days 5 and 6 of withdrawal of mycotoxins contaminated feed, respectively. The residues of OTA and AFB₁ were significantly lower in the tissues of hens fed these toxins concurrently compared with the groups fed OTA and AFB₁ independently. CONCLUSIONS: Residues of OTA and AFB₁ appeared in the tissues and eggs of laying hens kept on OTA‐ and AFB₁‐contaminated diets. Concurrent feeding of OTA and AFB₁ to hens significantly decreased the concentration of OTA and AFB₁ residues in the tissues and eggs. Copyright © 2011 Society of Chemical Industry     

Supplementary effect of aestivum wheat (Triticum aestivum L), bengal gram (Cicer arietinum L) and soya bean (Glycine max L) on protein quality of durum wheat (Triticum durum Desf)

Chapatis and parathas were made from different combinations of durum (Triticum durum Desf) and aestivum (Triticum aestivum L) wheat to test for their organoleptic acceptability. The best accepted durum/aestivum (40:60) combination was supplemented at 10, 20, 30 and 40% levels with Bengal gram (Cicer arietinum L) flour and soya protein (Glycine max L) concentrate. Raw and cooked samples were analysed for some amino acids and trypsin inhibitor activity. The most acceptable cooked products were fed to growing rats for estimation of protein efficiency ratio, apparent digestibility and plasma proteins. Cooking resulted in considerable losses in cystine, available lysine and trypsin inhibitor activity. The losses were greater in paratha than in chapati. Protein efficiency ratio and apparent N digestibility of chapatis were significantly higher than those of parathas. However, protein quality of soya-supplemented parathas was better than that of chapatis.     

Propagation of the Multi-Scalar Aggregative Standardized Precipitation Temperature Index and its Application

Water Resources Management - Nowadays, drought monitoring with various probabilistic indices has become common. However, the interpretation and applicability issues of multi-scalar drought indices...