Techniques for Improving Performance of Recommender Systems for Tourist Point of Interest Recommendation

Among the various applications of recommender systems, their use in estimating and suggesting points of interest (POIs) for tourists has expanded significantly in recent years. A common approach to identify user interests is to use collaborative filtering (CF) technique. However, the accuracy and efficiency of CF can be improved by applying different parameters and complementary approaches. In this paper, a new solution for promoting POI offers to tourists is presented, which uses a five-dimensional time model including the dimensions of day and night hours, days of the week, days of the month, months of the year, and occasions, and by calculating the Euclidean distance between the time of recommendation and the time of previous experiences of the active user and his similar users identifies and suggests suitable venues. The proposed solution also uses the trust parameter to increase the accuracy of POI suggestion. To improve the accuracy of trust evaluation, a new criterion based on a similarity tree structure between contexts is introduced. The results of experiments conducted on three well-known datasets show that the proposed model outperforms the state-of-the-art methods in term of efficiency and accuracy

The Study of the Possibility of Using Expired Ultraviolet Stabilizer (Tinuvin 770) in Polypropylene

TINUVIN 770 is a light stabilizer for stabilization of polymers, especially polypropylene against UV light that used worldwide. This compound has a high stability in dry conditions, away from direct sun light and in acidic condition is resistant to degradation and decomposition. The purpose of this research is the examination of the possibility of using expired TINUVIN 770 that besides the economic savings for the petrochemical industry, replace the applied method of using in expired materials in similar cases entering dozens toxic chemicals in Eco. This research is based on the identification methods of polymer additives such as high performance liquid chromatography coupled with ultraviolet spectroscopy(HPLC-UV), gas chromatography coupled with mass spectrometry(GC-MS) and comparison of the results obtained for the studied case (expired) and sample with date as the standard. Initially, DSC tests was performed on each sample to determine their thermal behavior. The FT-IR Spectrum of both samples was obtained. By UV-scan determined that both samples have UV absorbance in 270nm. The samples were analyzed by HPLC-UV, in this wavelength, and the same results were obtained for the two samples. Using GC-MS and comparison of the results obtained for the sample and standard it was proved the usability of   expired TINUVIN 770

The Study of the Possibility of Using Expired Ultraviolet Stabilizer (Tinuvin 770) in Polypropylene

TINUVIN 770 is a light stabilizer for stabilization of polymers, especially polypropylene against UV light that used worldwide. This compound has a high stability in dry conditions, away from direct sun light and in acidic condition is resistant to degradation and decomposition. The purpose of this research is the examination of the possibility of using expired TINUVIN 770 that besides the economic savings for the petrochemical industry, replace the applied method of using in expired materials in similar cases entering dozens toxic chemicals in Eco. This research is based on the identification methods of polymer additives such as high performance liquid chromatography coupled with ultraviolet spectroscopy(HPLC-UV), gas chromatography coupled with mass spectrometry(GC-MS) and comparison of the results obtained for the studied case (expired) and sample with date as the standard. Initially, DSC tests was performed on each sample to determine their thermal behavior. The FT-IR Spectrum of both samples was obtained. By UV-scan determined that both samples have UV absorbance in 270nm. The samples were analyzed by HPLC-UV, in this wavelength, and the same results were obtained for the two samples. Using GC-MS and comparison of the results obtained for the sample and standard it was proved the usability of   expired TINUVIN 770

Unveiling the Catastrophic Mechanism of Coal and Gas Outbursts: Strategies for Prevention and Control

In the realm of deep coal mining, a notable difficulty faced is the occurrence of methane gas and abrupt emissions of coal gas. This study scrutinizes coal gas outbursts via laboratory investigations. The study investigates the dynamics of coal gas outbursts, focusing on the analysis and mitigation of abrupt coal gas releases via laboratory experiments. Results suggest that the prevention of coal gas outbursts in the test sample is achievable by a 20% pressure reduction using degassing techniques.Drawing from engineering observations during the mining process, this study investigates the mechanism of coal gas outbursts using a specifically constructed test device. This study reveals that a gas outburst occurs when the boundaries of coal seams become unstable due to coal failure. In cases where fractures are not connected or are closed due to coal/rock stress, the fractured zones can maintain a certain level of carrying capacity due to self-sealing gas pressure. However, once the accumulated gas energy reaches a critical point, the coal seams become unstable, leading to gas outbursts. This study presents a laboratory analysis of coal gas outbursts, methane drainage, and methods for managing these events. Findings indicate that the outburst of coal gas can be effectively managed by lowering the tank pressure through gas drainage techniques

Solid phase extraction based on magnetic graphene oxide nanocomposite and ion mobility spectrometry for determination of bupropion

In this paper, a solid phase extraction based on magnetic graphene oxide nanocomposite has been introduced for the quantitative extraction of bupropion. The characterization and structural studies for the nanocomposite were carried out by fourier transform infrared spectrometry, scanning electron microscopy and X–ray diffraction techniques. Ion mobility spectrometry as a sensitive, rapid and simple method was applied for the determination of bupropion. The effect of experimental parameters (including desorption solvent: type and volume, adsorbent amount, pH, temperature and time extraction, and initial solution volume) on the extraction efficiency of the proposed method was investigated. Under optimum conditions, the calibration curves were linear in the two ranges of 4–10 and 10–24 ng with coefficients of determination R2≥ 0.98. The relative standard deviation was 5% and also the limits of detection and quantification were 0.66 and 2.20 ng, respectively. The proposed method was applied for the different brand tablets with various doses of bupropion which the satisfactory quantitative results were obtained (recovery: 88.0–92.0%)

Solid Phase Extraction Method for Separation and Pre-concentration of Thallium in Water Samples Using a Novel Adsorbent

In this study, a new and simple column-mode separation method has been proposed for the pre-concentration and removal of trace amounts of thallium(III) (Tl) from water samples. The procedure was based on sorption of Tl(III) ions by a solid phase extraction column filled with 4-[(2-hydroxy, 3-methoxy benzylidine)4-amino]1,2,4-treeazol-5-thione on microcrystalline naphthalene. The determination was performed directly using flame atomic absorption spectrometry (FAAS) method. The main factors affecting the extraction recovery were investigated and optimized. The interference effect of various ions on the determination of Tl(III) was also studied. In optimum conditions, the precision of the proposed method for sample solutions containing 0.2 µg/mL of Tl(III) was 2.0%, and the enrichment factor was found to be 35. The proposed method was evaluated and employed for pre-concentration and removal of Tl(III) from spiked natural (Tap and well) and industrial water samples

Concomitant Orbital Cavernous Hemangioma and Solitary Fibrous Tumor

Cavernous hemangiomas are the most frequent tumors in orbital region. Hemeangiopricytomas and solitary fibrous tumors are uncommon neoplasms found in different location, including the orbit. We present a 50-years-old man with coincide unilateral orbital cavernous hemangioma and solitary fibrous tumor. The initial diagnosis was orbital tumor. Computed tomography (CT) was performed. On CT two intraconal solid mass in right orbit positioned relatively near each other Antro-postriorly were observed. Tumors were excised totally with lateral orbitotomy method and sent for histopathologic examination. To our knowledge, only one case report of splenic hemangiopricytoma adjacent to cavernous hemangioma of colon has been reported in the literature. Our case shows the coincidence of hemangiopricytoma adjacent to cavernous hemangioma is possible and should be considered

Date Fruit Extract Is a Neuroprotective Agent in Diabetic Peripheral Neuropathy in Streptozotocin-Induced Diabetic Rats: A Multimodal Analysis

Background. To study the effects of an aqueous extract of date fruit (Phoenix dactylifera L. Arecaceae) diet on diabetic polyneuropathy (DPN) in streptozotocin- (STZ-) induced diabetic rats. Methods. The effects of a date fruit extract (DFE) diet on diabetic neuropathy in STZ-induced diabetic rats were evaluated and compared with a nondiabetic control group, diabetic control group (sham), and vehicle group with respect to the following parameters: open field behavioral test, motor nerve conduction velocity (MNCV), and morphological observations. Results. In the model of STZ-induced of diabetic neuropathy, chronic treatment for 6 weeks with DFE counteracted the impairment of the explorative activity of the rats in an open field behavioral test and of the conduction velocity of the sciatic nerve (MNCV). In addition, pretreatment with DFE significantly reversed each nerve diameter reduction in diabetic rats. Conclusion. DFE treatment shows efficacy for preventing diabetic deterioration and for improving pathological parameters of diabetic neuropathy in rats, as compared with control groups

Comparison of Propofol and Isoflurane Effects on Intraocular Pressure among Patients Undergoing Lumbar Disc Surgery

Purpose: Blindness is a catastrophic complication of surgeries performed in prone position which occurs mainly due to hemodynamic alterations and the relevant effects on optic nerve perfusion. In this study, we compared the effects of Propofol and Isoflurane on intraocular pressure among patients undergoing lumbar disk surgery.Patients and Methods: In this randomized clinical trial, 60 patients who were candidates for lumbar disk surgery were randomly assigned into two groups: Propofol and Isoflurane groups. Intraocular Pressure was measured before and after induction of anesthesia in supine position, immediately after prone positioning of the patient and at the end of operation in prone position and also after turning the patients back to supine position. Mean arterial pressure, systolic and diastolic blood pressure and heart rates were also assessed.Result: The baseline Mean Intraocular Pressure among awake patients in supine position in Isoflurane and Propofol groups were 15.8 ± 3.1 and 18.2 ± 5.4 mmHg respectively. At the end of operation intraocular pressure in prone position in these two groups of patients changed to 18 ± 5.8 and 17.2 ± 4.9 mmHg respectively (P = 0.024) indicating a statistically significant difference in change. According to mixed analysis, mean arterial pressure, systolic blood pressure, diastolic blood pressure, end tidal Co2 and heart rate did not show statistically significant difference between the two groups (P < 0.05).Conclusion: Propofol better controls the intraocular pressure compared to Isoflurane in prone position among patients undergoing lumbar disk surgery with no significant difference in hemodynamic responses. Keywords: Intraocular pressure; prone; position; surgery; Propofol; Isoflurane