scholarly journals Evaluation of Various Surface Cleaning Techniques Inside Tunnels on Pavement Skid Resistance

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5660
Author(s):  
José Ramon Marcobal ◽  
Freddie Salado ◽  
Gerardo Flintsch

A request started a comprehensive investigation on the Skid Resistance (SR) inside a highway tunnel in Madrid, Spain, to determine methods that will improve or maintain the SR above the minimum required level (60), after the application of Hydroblasting, without the need of pavement surface rehabilitation. The right lane located on eight sections inside tunnel XC was used as a test section, in which three went thru the application of water pressure applied weekly, biweekly, and monthly. Three other sections for surface sweeping at the same frequencies and two untreated sections as control. Using the Microgriptester, weekly SR measurements taken before and after tracked the pavement response. Results showed that SR decreased weekly depending on the frequency of the treatment applied and for higher frequencies, SR was almost at the same level. Water pressure and sweeping applied weekly, biweekly, and monthly, during the two months testing period, maintained the SR level above the required value of 60 and the untreated sections showed that pavement surface must be treated to maintain the SR above 60.

1996 ◽  
Vol 76 (2) ◽  
pp. 849-866 ◽  
Author(s):  
W. Jiang ◽  
T. Drew

1. A quantitative and longitudinal analysis of locomotion was made after bilateral lesions of the dorsolateral funiculi (DLF) and/or the dorsal columns (DC) in the lower thoracic cord (T12 or T13) in five adult cats. All cats were chronically implanted several weeks before the spinal cord lesion to permit the recording of electromyographic (EMG) activity from selected flexor and extensor muscles of the fore- and hindlimbs of each side. This allowed each cat to act as its own control when comparing the pattern and amplitude of EMG activity before and after the lesion. All experiments were also videotaped to allow an analysis of the kinematic changes before and after the lesions. Kinematic data were only analyzed for the side of the cat facing the camera; for all cats this was the left side. 2. After recovery periods of 2-5 mo, wheat-germ-agglutinated horseradish peroxidase (WGA-HRP) was injected caudal to the lesion site (normally at L2). The extent of the lesion was verified both histologically and by evaluating the number of HRP-labeled neurons in different supraspinal structures. These analyses showed that the cortico- and rubrospinal tracts (CST and RST, respectively) were completely interrupted, bilaterally, in two of five of the cats; in one of these cats the DCs were also interrupted. In the other three cats there was more variable damage, and the CST and RST were only completely interrupted on the right side of one of these animals. The DCs were completely sectioned in two of these cats. 3. During the 1st wk subsequent to the lesion, most cats had difficulty in supporting their weight and in walking. However, within 10 days all were able to walk, unaided, for extended periods on the treadmill at speeds of at least 0.35 m/s. In the two cats with the complete, bilateral DLF lesions, the animals dragged both their left and right hindpaws along the treadmill belt during the swing phase of the step cycle (paw drag) throughout the testing period of 3-5 mo. In the other three cats, paw drag in either hindlimb was only seen in the 1st 2-3 wk after the lesions, with the exception of the cat with the complete lesion of the DLF on the right side, which showed sustained paw drag in the right hindlimb throughout the testing period. 4. Significant increases in step cycle and swing duration following the lesion were observed only in the two cats with the largest lesions. In all five cats, statistical comparisons of the slopes from a linear regression analysis showed that the relationship between swing and step cycle duration was unchanged by the lesions. 5. Joint angles in the left hindlimb of the two cats with the largest lesions were generally smaller (more flexed) than in the prelesion controls. This was particularly true for the knee and ankle joints. The other three cats showed changed joint angle values for the hip, knee, and ankle only in the 1st 2-3 wk after the lesions. All of the cats, except the one with the least damage to the left DLF, exhibited increased joint excursions at the metatarsophalangeal (MTP) joint of the left limb throughout the recovery period. 6. There were sustained changes in the coupling between the hip and the knee of the left limb, together with smaller changes in the coupling of the knee and ankle in the two cats with the complete lesions of the DLF. In contrast to the prelesion controls, flexion at the ankle occurred before swing onset in these same two cats. The changes in the coordination between the hip and the knee were associated with changes in the temporal coupling between the hip flexor, sartorius (Srt), and the knee flexor, semitendinosus (St). Despite some improvement, the coupling between these two muscles never fully recovered to the prelesion values. Similar, but smaller, changes in the delay between Srt and St were also seen in two of the other three cats. (ABSTRACT TRUNCATED)


1992 ◽  
Vol 68 (05) ◽  
pp. 500-505 ◽  
Author(s):  
Ch M Samama ◽  
Ph Bonnin ◽  
M Bonneau ◽  
G Pignaud ◽  
E Mazoyer ◽  
...  

SummaryWe investigated the comparative antithrombotic properties of clopidogrel, an analogue of ticlopidine, and aspirin, using the Folts' model on femoral arteries in 22 pigs. On each animal, clopidogrel or aspirin were used to treat the thrombotic process on the left femoral artery and to prevent this process on the right femoral artery. Sequentially: an injury and stenosis were carried out on the left femoral artery; the thrombotic process was monitored with a Doppler during a 30-min observation period for cyclic flow reductions or permanent cessation of flow; after the first cyclic flow reduction occurred, clopidogrel (5 mg kg-1) or aspirin (2.5, 5, 100 mg kg-1) were injected intravenously; if cyclic flow reductions were abolished, epinephrine (0.4 µg kg-1 min-1) was injected to try to restore cyclic flow reductions and/or permanent cessation of flow; then injury and stenosis were applied on the right femoral artery. Before and after injection of clopidogrel or aspirin, ear immersion bleeding times and ex-vivo platelet aggregation were performed. Clopidogrel (n = 7) abolished cyclic flow reductions in all animals and epinephrine did not restore any cyclic flow reduction. On the right femoral artery, cyclic flow reductions were efficiently prevented, even for two injuries. Basal bleeding time (5 min 28) was lengthened (>15 min, 30 min after clopidogrel and remained prolonged even after 24 h). ADP-induced platelet aggregation was inhibited (more than 78%). Comparatively, aspirin had a moderate and no dose-dependent effect. Aspirin 2.5 mg kg-1 (n = 6) abolished cyclic flow reductions in 2 animals, CFR reoccurred spontaneously in one animal and epinephrine restored it in a second animal. Aspirin 5 mg kg-1 (n = 6) abolished cyclic flow reductions in only 3 animals and epinephrine always restored it. Aspirin 100 mg kg-1 (n = 3) was unable to abolish cyclic flow reductions. On the right femoral artery, aspirin did not significantly prevent cyclic flow reductions which occurred in all animals after one (n = 14) or two injuries (n = 1), except for one animal. Basal bleeding time was lengthened but it shortened rapidly, reaching its basal value after 24 h. ADP-induced aggregation was not significantly inhibited, whereas arachidonic acid induced aggregation was always inhibited. Clopidogrel appears as a more potent antithrombotic drug than aspirin in this model, in treating and preventing spontaneous or epinephrine-induced cyclic flow reductions and lengthening bleeding time.


2013 ◽  
Vol 19 (1) ◽  
pp. 28
Author(s):  
Hamda Situmorang ◽  
Manihar Situmorang

Abstract Implementation of demonstration method in the teaching of chemistry is assigned as the right strategy to improve students’ achievement as it is proved that the method can bring an abstract concept to reality in the class. The study is conducted to vocational high school students in SMKN1 Pargetteng getteng Sengkut Pakfak Barat at accademic year 2013. The teaching has been carried out three cycles on the teaching of chemistry topic of colloid system. In the study, the class is divided into two class, experiment class and control class. The demontration method is used to teach students in experimental class while the teaching in control class is conducted with lecture method. Both are evaluated by using multiple choise tests before and after the teaching procedures, and the ability of students to answer the problems are assigned as students’ achievements. The results showed that demonstration method improved students’ achievement in chemistry. The students in experimental class who are taughed with demonstration method (M=19.08±0.74) have higher achievements compare with control class (M=12.91±2.52), and both are significantly different (tcalculation 22.85 > ttable 1.66). The effectivity of demostration method in experimental class (97%) is found higer compare to conventional method in control class (91%).


Author(s):  
Ikhsan Fuady ◽  
Rangga Saptya MP

<p align="center"><strong>Abstrak</strong></p><p><em>Pemanfaatan game dikalangan remaja memiliki peran yang efektif sebagai wadah untuk hiburan. Tetapi pemanfaatan game tidak tepat memiliki efek samping game terhadap kehidupan sehari hari remaja, mulai dari kurang bersosialIsasi hingga perilaku kekerasan dikalangan remaja. Penyuluhan terhadap remaja bertujuan untuk memberikan pemahaman kepada remaja tentang variasi game berdasarkan rating pengguna, maupun cerdas dalam manajemen penggunaan game dalam kehidupan remaja sehari hari. Pengetahuan remaja tentang varian/ragam game berdasarkan rating relatif rendah sebagaian besar pemengetahuannya tersebar pada kategori sangat rendah dan rendah yaitu sebesar 65 persen. Metode edukasi dan sosialisasi ini adalah dengan beberapa tahapan. Tahap pertaman tim pengabdian memberikan edukasi dan diskusi tentang beragam bentuk game, karakteristik, serta karakteristik pengguna game yang tepat. Selanjutnya beberapa permainan dan kuis untuk meingkatkan literasi remaja tentang pemanfaatan game secara bijak. Kegiatan penyuluhan ini mampu meningkatkan pemahaman para remaja dalam mengenali game yang baik digunakan, hal ini dapat dilihat dari peningkatan pengetahuan remaja relatif signifikan sebelum dan sesudah penyuluhan.</em></p><p><strong>Kata kunci<em>:</em></strong><strong><em> </em></strong><strong><em>Edukasi, Game, Penyuluhan </em></strong></p><p align="center"><em> </em></p><p align="center"><strong>Abstract</strong> </p><p><em>The use of games among teenagers has an effective role as a forum for entertainment. But the improper use of games has the side effects of games on the daily lives of adolescents, ranging from lack of socialization to violent behavior in adolescents. Counseling against adolescents aims to provide understanding to adolescents about the variety/variance of games based on user ratings, as well as being smart in managing game use in daily teenage life. Teenagers' knowledge about game variants/based on the rating is relatively low, most of the knowledge is spread in the very low and low categories, which is 65 percent. The method of education and outreach is by several stages. The first stage of the dedicated team provided education and discussion about various forms of games, characteristics, and characteristics of the right game user. Furthermore, some games and quizzes to improve teen literacy about game use wisely. This counseling activity can increase the understanding of teenagers in recognizing games that are well used, this can be seen from the relatively significant increase in adolescent knowledge before and after counseling.</em></p><p><strong>Keywords<em>:</em></strong><em> <strong>Education, Games, Counseling</strong></em></p>


Work ◽  
2021 ◽  
pp. 1-8
Author(s):  
Fabiana Foltran Mescollotto ◽  
Érica Brito Gonçalves ◽  
Ester Moreira de Castro Carletti ◽  
Ana Beatriz Oliveira ◽  
Elisa Bizetti Pelai ◽  
...  

Background: Excessive use of smartphones may be associated with behavioral and physical health changes and might cause musculoskeletal alterations in the head and neck region. Objective: To evaluate the prevalence of smartphone addiction in college students and its correlation with symptoms of head and neck pain and masticatory and trapezius muscle activity while resting, before and after smartphone use. Methods: Twenty university students participated in the study. They answered the Smartphone Addiction Scale and the Fonseca Anamnestic Index. Next, the participants were seated and prepared for electromyography through the placement of surface electrodes on the masseter, temporal, and trapezius muscles. Rest condition data were collected for 10 seconds before and after 30 minutes of smartphone use. Results: The results showed that 35% of the evaluated individuals were classified as smartphone addicted and 35% reported no head or neck pain in the previous 30 days. There was no association between smartphone use and head and neck pain. In the electromyography, there was an increase in RMS values after smartphone use in the right and left masseter muscles and the left trapezius. Conclusion: College students presented a high prevalence of smartphone addiction and head and neck pain, but these were not statistically associated. There was a change in muscle activity only in the right trapezius muscles before and after 30 minutes of smartphone use. These findings are contrary to the current belief that the use of smartphones correlates with pain in the neck region and changes in the electrical muscle activity, leading to fatigue in the cervical muscles.


Author(s):  
Sergey Dydykin ◽  
Friedrich Paulsen ◽  
Tatyana Khorobykh ◽  
Natalya Mishchenko ◽  
Marina Kapitonova ◽  
...  

Abstract Purpose There is no systematic description of primary anatomical landmarks that allow a surgeon to reliably and safely navigate the superior and posterior mediastinum’s fat tissue spaces near large vessels and nerves during video-assisted endothoracoscopic interventions in the prone position of a patient. Our aim was to develop an algorithm of sequential visual navigation during thoracoscopic extirpation of the esophagus and determine the most permanent topographic and anatomical landmarks allowing safe thoracoscopic dissection of the esophagus in the prone position. Methods The anatomical study of the mediastinal structural features was carried out on 30 human cadavers before and after opening the right pleural cavity. Results For thoracoscopic extirpation of the esophagus in the prone position, anatomical landmarks are defined, their variants are assessed, and an algorithm for their selection is developed, allowing their direct visualization before and after opening the mediastinal pleura. Conclusion The proposed algorithm for topographic and anatomical navigation based on the key anatomical landmarks in the posterior mediastinum provides safe performance of the video-assisted thoracoscopic extirpation of the esophagus in the prone position.


2021 ◽  
Vol 22 (Supplement_1) ◽  
Author(s):  
KIRILL Malikov ◽  
MARINA Kirichkova ◽  
MARIA Simakova ◽  
NARECK Marukyan ◽  
OLGA Moiseeva

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Chronic thromboembolic pulmonary hypertension (CTEPH) leads to a progressive increase in pulmonary vascular resistance (PVR) and pulmonary artery pressure (PAP) with the development of severe dysfunction of the right heart and heart failure. Mortality for three years with an average pressure in the pulmonary artery (PA) of more than 50 mmHg is more than 90%. Balloon pulmonary angioplasty (BPA) has a significant advantage over other methods of surgical treatment, but it requires the determination of additional non-invasive markers of effectiveness. Transthoracic echocardiography (TTE) remains the main method for assessing the morphology and function of the heart. Purpose Compare different indicators reflecting the severity of CTEPH with TTE indicators before and after BPA. To evaluate the effectiveness of using BPA for the treatment of patients with CTEPH using routine TTE and speckle tracking mode. Materials and methods For 18 months 30 patients without concomitant cardiovascular pathology were subjected to several BPA sessions. Before treatment, 50% of patients belonged to the 3 CTEPH functional class (FC), 40% to 2 FC, 10% to 1 FC. The average number of sessions was 4.7 ± 1.3. Before the first BPA and after the last, all the patients were performed: six-minute walk test (6MWT, metres), Borg scale (in points), test for NT-proBNP (pg/ml); TTE with assessment of the right ventricle (RV) and left ventricle (LV) including areas of the right atrium (aRA, cm2), mean pulmonary artery pressure (PUPM,mmHg),RV free wall strain (GLSFW, %), RV free wall strain rate (GLSRFW, sm/sec), RV free wall postsystolic shortening (PSSFW, %), tricuspid annular plane systolic excursion (TAPSE, sm), tricuspid annulus systolic velocity (TASV, sm/sec). Results. Before the first BPA session, the 6MWT in the patient group averaged 315.9 ± 9.08 metres, after - 439.5 ± 11.45 m; the Borg from 5.4 ± 0.94 points decreased to 4 ± 1.01 points; NT-proBNP before the treatment was 1513 ± 13.01 pg/ml, after - 171 ± 6.09; according to TTE the ratio of RV/ LV before and after treatment was 1.31 ± 0.02 and 0.97 ± 0.04; aRA was 29.3 ± 4.87 and 22.3 ± 3.53 cm2; basal RV - 52 ± 5.11 and 44 ± 7.26 mm; PUPM decreased from 76.6 ± 7.65 to 31.3 ± 3.78 mmHg; GLSFW from -14.69 ± 2.33 came to 17.5 ± 3.45 %; GLSRFW with -0.9 ± 0.09 to -1.7 ± 0.11 cm/sec; TAPSE from 16.7 ± 1.87 to 18.2 ± 2.34 cm; TASV from 10.11 ± 1.45 to 12.25 ± 1.98 cm/s, PSSFW before treatment was -18.4 ± 1.2%, after treatment in 66% of patients disappeared, in 34% became an average of 17.4 ± 0.9% The distribution of STEPH FC has also changed. Conclusion. BPA leads to an improvement in the tolerance of physical activity, clinical indicators, and parameters of central hemodynamics in the pulmonary circulation, evaluated according to direct manometry, and leads to reverse remodeling of the RV in the long term. Performing a staged BPA leads to an improvement in the functional parameters of contractility of the RV.


2019 ◽  
Vol 34 (6) ◽  
pp. 1199-1207
Author(s):  
Thorir Svavar Sigmundsson ◽  
Tomas Öhman ◽  
Magnus Hallbäck ◽  
Eider Redondo ◽  
Fernando Suarez Sipmann ◽  
...  

AbstractRespiratory failure may cause hemodynamic instability with strain on the right ventricle. The capnodynamic method continuously calculates cardiac output (CO) based on effective pulmonary blood flow (COEPBF) and could provide CO monitoring complementary to mechanical ventilation during surgery and intensive care. The aim of the current study was to evaluate the ability of a revised capnodynamic method, based on short expiratory holds (COEPBFexp), to estimate CO during acute respiratory failure (LI) with high shunt fractions before and after compliance-based lung recruitment. Ten pigs were submitted to lung lavage and subsequent ventilator-induced lung injury. COEPBFexp, without any shunt correction, was compared to a reference method for CO, an ultrasonic flow probe placed around the pulmonary artery trunk (COTS) at (1) baseline in healthy lungs with PEEP 5 cmH2O (HLP5), (2) LI with PEEP 5 cmH2O (LIP5) and (3) LI after lung recruitment and PEEP adjustment (LIPadj). CO changes were enforced during LIP5 and LIPadj to estimate trending. LI resulted in changes in shunt fraction from 0.1 (0.03) to 0.36 (0.1) and restored to 0.09 (0.04) after recruitment manoeuvre. Bias (levels of agreement) and percentage error between COEPBFexp and COTS changed from 0.5 (− 0.5 to 1.5) L/min and 30% at HLP5 to − 0.6 (− 2.3 to 1.1) L/min and 39% during LIP5 and finally 1.1 (− 0.3 to 2.5) L/min and 38% at LIPadj. Concordance during CO changes improved from 87 to 100% after lung recruitment and PEEP adjustment. COEPBFexp could possibly be used for continuous CO monitoring and trending in hemodynamically unstable patients with increased shunt and after recruitment manoeuvre.


1985 ◽  
Vol 248 (1) ◽  
pp. H89-H97 ◽  
Author(s):  
N. Takahashi ◽  
M. J. Barber ◽  
D. P. Zipes

The route efferent vagal fibers travel to reach the left ventricle is not clear and was the subject of this investigation. We measured left ventricular and septal effective refractory period (ERP) changes during vagal stimulation and a constant infusion of norepinephrine, before and after phenol was applied at selected sites of the heart to interrupt efferent vagal fibers that may be traveling in that area. Phenol applied to the atrioventricular (AV) groove between the origin of the right coronary artery anteriorly to the posterior descending branch of the circumflex coronary artery completely eliminated vagal-induced prolongation of ERP in the anterior and posterior left ventricular free wall and reduced, but did not eliminate, ERP prolongation in the septum. A large (3-cm radius) epicardial circle of phenol prevented vagal-induced ERP prolongation within the circle in all dogs, while a small (1-cm radius) epicardial circle of phenol failed to prevent vagal-induced ERP changes within the circle in any dog. An intermediate (2-cm radius) circle eliminated vagal effects on ERP in 13 of 18 dogs. Arcs of phenol, to duplicate the upper portion of the circle, applied sequentially from apex to base eliminated efferent vagal effects only when painted near or at the AV groove. We conclude that the majority of efferent vagal fibers enroute to innervate the anterior and posterior left ventricular epicardium cross the AV groove within 0.25-0.5 mm (depth of phenol destruction) of the epicardial surface.(ABSTRACT TRUNCATED AT 250 WORDS)


2014 ◽  
Vol 501-504 ◽  
pp. 178-184
Author(s):  
Kai Yang ◽  
Shu Ran Lv ◽  
Chun Xue Wang

Mining companies intend to solve the problem of waste dump and reduce the production cost by dumping a large number of waste soils to cover slope outside the running tailings. Therefore, in order to discuss the safety of waste dump slope covering in front of the tailings dam, numerical method was adopted to study the seepage-line change law, the pore water pressure and anti-sliding safety before and after the waste dump covering out of tailings dam. The researches show that the key to waste-dump slope safety are the drainage performance of waste dump bottom layer and the anti-sliding safety of waste dump soil. The appropriate waste dump slope work can improves the tailings dams safety and solves the waste dump problem in mining production.


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