533 research outputs found
Infrared Thermography And High Accuracy Gps For Automated Asphalt Crack Detection
Roads are major public assets. The USA spends billions of dollars each year on road construction and maintenance. To keep these roads in a healthy condition and for better planning and allocation of maintenance budgets, knowledge of distressed locations is needed. Roads develop cracks when they are subjected to stresses that exceed their designed criteria or their materials properties. Early detection and repair of cracks has proven to be the most cost-effective strategy in limiting the damage to roads and reducing expenditures. Various methodologies of crack detection were developed and significant techniques were made in the last few years. One of the most important recent technologies is the infrared thermography, which allows the use of infrared waves for crack detection. Another important technology is the global navigation satellite system (GNSS) which currently includes the GPS and GLONASS constellations. With the help of these systems, accurate location coordinates (longitude, latitude and altitude) up to a few centimeters were located. The objective of this research is to test the combined use of GNSS and infrared thermography in an automated system for the detection of asphalt cracks and their locations. To achieve this goal, two tests have been conducted. The first one, regarding the location tagging, was done using two pairs of GPS receivers which can detect signals from both GPS and GLONASS navigation systems in single and dual frequencies (L1 and L2). Different modes have been set to the receiver and comparison graphs were developed to compare accuracies against modes. The second test involves an infrared camera mounted on a car and moving in speeds approaching highway speed limit. The images obtained from the camera were processed using cracks detection software to analyze cracks properties (length, width, density and severity). It was found that the images that were taken by a moving infrared camera were recognized by crack detection software for moving speeds up to 50 mph. At speeds higher than 50 mph, images were blurred. As for location test, The GLONASS combined by GPS receivers got slightly better results than GPS only in both dual and single frequencies. The GLONASS satellites are not always available in view and when they are there, the number of satellites that can be detected by receiver range from one to three satellites at the most and for only a short period of time. It is recommended that future research be conducted to investigate the effect of using different camera lenses on the clarity of the images obtained as well as the effect of raising the camera level above the pavement surface in such a way that the whole lane width (12 ft.) would be covered in one image. Also the total reliance on GPS only receivers in determining cracks location has proven to be enough for this application
Blood lead level in relation to awareness and self reported symptoms among gasoline station workers in the Gaza strip
Background: Leaded gasoline is being used in Gaza Strip. Measurements of blood lead level (BLL) and relate it to awareness of gasoline station workers would be helpful in lead protection programs.
Purpose: To determine BLL and to assess its relation to awareness and self reported symptoms among gasoline station workers in the Gaza Strip.
Methods: A cross section of 72 workers was asked to fill in a questionnaire. BLL was determined by atomic absorption spectrometry.
Results: Thirty four (47.2%) workers had BLL> 10? g/dl. The mean BLL was inversely related to the education level (p= 0.001). Workers worked d5 years in the station had lower BLL than those worked> 5 years (7.8±5.6 v 12.5±5.8? g/dl, p= 0.004). The variation in workers knowledge by their BLL was not significant. Higher BLL was generally found in workers who did not practice protective measures compared to those who did, with significant difference for respiratory mask (12.4±5.9 v 5.6±1.6? g/dl, p= 0.001), gloves (13.1±6.0 v 8.6±4.9? g/dl, p= 0.001) and frequent milk drink (13.5±6.0 v 9.3±5.2? g/dl, p= 0.018). Higher BLL was also found in workers who reported symptoms than in those who did not, with significant differences for irritability (12.4±5.4 v 9.2±5.6? g/dl, p= 0.031), headache (12.2±5.8 v 9.0±5.9? g/dl, p= 0.046), concentration difficulties (12.9±5.8 v 9.4±5.6? g/dl, p= 0.015), sleep disturbances (14.1±5.8 v 8.9±5.0? g/dl, p= 0.001) and hypertension (13.3±6.4 v 8.1±2.9? g/dl, p= 0.001).
Conclusions: High BLL was associated with low education level, long work duration, lack of protective measures and increase self reported symptoms. Educational programs on
New modification on feistel DES algorithm based on multi-level keys
The data encryption standard (DES) is one of the most common symmetric encryption algorithms, but it experiences many problems. For example, it uses only one function (XOR) in the encryption process, and the combination of data is finite because it occurs only twice and operates on bits. This paper presents a new modification of the DES to overcome these problems. This could be done through adding a new level of security by increasing the key space (using three keys) during the 16 rounds of the standard encryption algorithm and by replacing the predefined XOR operation with a new # operation. Our proposed algorithm uses three keys instead of one. The first key is the input key used for encrypting and decrypting operations. The second key is used for determining the number of bits, while the third key is used for determining the table numbers, which are from 0 to 255. Having evaluated the complexity of our proposed algorithm, the results show that it is the most complex compared with the well-known DES and other modified algorithms. Consequently, in our proposed algorithm, the attacker try a number of attempts 21173 at minimum to decrypt the message. This means that the proposed DES algorithm will increase the security level of the well-known DES
Product differentiation, market dynamics and the value relevance of trade payables: Evidence from UK listed firms
This paper provides a comprehensive evidence on how product and market dynamics affect the value relevance of trade payables. Using a sample of 2559 UK listed firms over the period 2005–2014, we find a positive relationship between trade payables and firm performance. Our evidence suggests that trade payables increase (decrease) performance in firms with differentiated products and demand uncertainty (larger market share). We demonstrate that the relative value relevance of bank credit versus suppliers’ credit is dependent on the nature of the product, the level of sales volatility, and market share. We use an innovative approach to assess the robustness of our results to omitted variable bias
Association of Resistin, Visfatin, and Osteoprotegerin in Diabetes Mellitus
The aims of the study to evaluate the association between diabetes mellitus and resistin, visfatin and osteoprotegerin levels and studying the interaction of resistin, visfatin and osteoprotegerin with duration of diabetes mellitus. This is a case/control study conducted on a total 88 subjects; sixty eight patients (25 male and 43 female) compared to twenty healthy persons (7 males and 13 females). Venous blood collected from the patients attending to Diabetic Center in Merjan Teaching Hospital / Babylon/ Iraq. Serum was prepared from collected blood, and used to investigate resistin, vistatin and osteoprotegerin. The present study findings revealed a significant decrease in resistin, visfatin and osteoprotegerin levels when compared with controls. On other the hand, the study showed that the visfatin and osteoprotegerin increased in 11-15 years of duration of diagnosis, while there was no relation between resistin and duration of diagnosis. Keywords: Diabetes Mellitus, resistin, visfatin and osteoprotegerin
Homocysteine and hematological indices in hemodialysis patients
Objectives:
To explore the relationship between homocysteine and various hematological indices in hemodialysis patients.
Patients and Methods:
This case-control study comprised 60 hemodialysis patients and 60 healthy controls matched for gender and age. Hemodialysis duration was 3.2±2.9 year at frequency of 2.6±0.6/week. Hypertension and diabetes were the most common self-reported disorders among the hemodialysis patients.
Results:
Serum homocysteine was significantly higher in hemodialysis patients than in controls (50.8±9.7 vs. 13.1±3.7 μmol/l, P= 0.000). White blood cell (WBC) and platelet (PLT) counts were significantly higher in hemodialysis patients than in controls [(7.18±2.37 x109/L and 266.3±111.9 x109/L vs 5.95±1.37 x109/L and 222.0±54.1 x109/L) with P= 0.017 and P= 0.045, respectively]. In contrast, red blood cell (RBC), hemoglobin, and hematocrit were significantly lower in hemodialysis patients (3.1±0.5 x1012/L, 8.9±1.5 gm/dl and 26.3±4.6%) than in controls (4.0±0.4 x1012/L, 12.8±1.6 gm/dl and 45.0±4.6%) with P= 0.000. Prothrombin time (PT) and international normalized ratio (INR) were significantly higher in hemodialysis patients compared to controls (16±3 sec and 1±0 vs. 14±0 sec and 1.0±0.1, P= 0.000), whereas activated partial thromboplastin time (APTT) was significantly decreased in hemodialysis patients (25±5 vs 33±2 sec, P= 0.000). Homocysteine correlated directly with WBC count (r= 0.338, P= 0.008) and PLT count (r= 0.369, P= 0.000) whereas inverse correlations were found between homocysteine and RBC count (r=-0.648, P= 0.000), hemoglobin (r=-0.733, P= 0.000) and hematocrit (r=-0.836
Impact of Age on Ovarian Response and IVF Outcome during Controlled Ovarian Hyperstimulation in Women from Gaza Strip
Background: Although age is an important factor in female fertility, not much date were focused on the relationship between age and ovarian response and in vitro fertilization (IVF) outcome. However, the female reproductive capacity varies with age.
Objective: To assess the impact of age on ovarian response and IVF outcome during controlled ovarian hyperstimulation in women from Gaza Strip.
Methods: This prospective cohort study consisted of 75 women attending IVF at Al-Basma Fertility Center in Gaza City. The number of oocytes and embryos were recorded for each female and the occurrence of pregnancy was followed for three months. The obtained data were computer analyzed using SPSS statistical package version 18.
Results: The mean age of the study population was 29.2±5.9 years. The total number of oocytes was significantly decreased with increasing age (F= 3.932 and P= 0.024). In this context Pearson correlation test exhibited negative significant correlation between women age and the number of mature oocyte (r=-0.276, P= 0.017). There was an inverse relationship between age and ovarian response (F= 6.773 and P= 0.001), showing good response (9-16 oocytes) at mean age of 26.7±5.0 years. When related to women age, IVF outcome showed that the chance of getting pregnant increased with decreased age (F= 4.278 and p= 0.018).
Conclusion: The ovarian response and the chance of getting pregnancy were diminishing with ageing, implying that maternal age should by consider during IVF program
Effect of Dietary Supplementation of Flavomycin on the Growth Performance, Digestibility Traits, Carcass Characteristics, Carcass Meat Chemical Analysis and Some Blood Components of Lambs
Abstract: The aim of this study was to determine the effects of flavomycin added to the diets on growth performance, digestibility traits, carcass characteristics, carcass meat chemical analysis and some blood components of lambs. Thirty lambs at six months -old were randomly allocated to five groups, with six in each. The dietary treatments were: 1. Basal diet (control); 2. Basal diet + 25 mg flavomycin/kg diet; 3. Basal diet + 50 mg flavomycin/kg diet, 4. Basal diet + 75 mg flavomycin/kg diet and 5. Basal diet + 100 mg flavomycin/kg diet. Body weight gain, feed consumption and feed conversion were determined weekly. Carcass and carcass chemical analysis were determined at the end of the study. There were significant effects of dietary treatments on body weight gain and feed conversion during the experimental period. The addition of flavomycin to the diet was resulted a significant higher body weight gains, better-feed efficiency and improved digestibility traits as compared to that of control group. Also, the supplementation of diet with flavomycin was increased tail fat weight and abdominal fat weight. It was found that carcass weight, carcass yield and dressing percentage were significantly affected by flavomycin additions. It was concluded that the addition of flavomycin improved growth performance, digestibility traits and carcass characteristics of lambs
Hormonal and Histological Aspects of Germ Cell Aplasia among a Group of Infertile Men in Gaza Strip
Background: Germ cell aplasia is a type of azoospermia characterized by hormonal abnormalities as well as histopathological features.
Objective: To assess hormonal and histological aspects of germ cell aplasia among infertile men in Gaza Strip.
Materials and methods: A total of 375 infertile men visiting the Specialized Medical Centers in Gaza strip were subjected for testicular biopsy. Out of them 74 showed germ cell aplasia. They were interviewed to fill in a questionnaire and blood samples were drawn for determination of testosterone, prolactin, luteinizing hormone (LH) and follicular stimulating hormone (FSH). Forty four fertile men served as controls. Data were computer analyzed using SPSS/ PC, version 18.0.
Results: Germ cell aplasia represented 74 (19.7%) among azoospermic men in Gaza Strip as indicated by testicular biopsy. The mean age of patients and controls was 29.9±5.9 and 31.2±5.7 years, respectively. Medical history showed that varicocele and hormonal problems were significantly higher in patients than controls (P=0.042 and P=0.008, respectively). The number of patients who had abnormal levels of testosterone, prolactin, LH and FSH were 44 (59.5%), 36 (48.6%), 57 (77.0%) and 67 (90.5%) compared to controls of 7 (15.9%), 7 (15.9%), 2 (4.5%) and 13 (29.5%), respectively with c2=21.326, P=0.000; c2=12.098, P=0.000; c2=55.122, P=0.000 and c2=47.020, P=0.000, respectively. Testicular biopsy revealed that infertile men with germ cell aplasia showed Sertoli cell only with partial atrophy, Sertoli cell only with Leyding cell hypoplasia and Sertoli cell only with interstitial fibrosis.
Conclusions: Hormonal abnormalities and histopathological features were identified in germ cell aplasia
Climate Change Survey Measures: Exploring Perceived Bias and Question Interpretation
Climate change has become an important yet politically divisive topic in recent years. Further complicating the issue are assertions that climate change– related public opinion surveys used by social scientists are biased or otherwise problematic. We conducted a pilot study to explore questions concerning bias and interpretation of climate change surveys. Our study sample was composed of adult residents of Nebraska (n = 115). We augmented our survey findings with cognitive interviews of a subsample of respondents (n = 20). We assessed study participants’ attitudes about climate change, and perceptions of bias and interpretation of survey questions drawn from previously used survey instruments and national polls. Among our study sample, we found little support for perceived bias within the survey items employed. However, interview findings indicated that particular survey language may have elicited unexpected associations among respondents. We discussed implications for further research
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