Lateral landfill gas migration : characterization and preliminary modeling results

International audienceLateral landfill gas migration occurs in the surroundings of a MSW landfill with capped old waste cells. Three areas were identified by poor vegetation growth. Methane flux chamber measures confirm the extent of these areas, as observed in the cultivated land. These measures and some complementary physical measures were used to build a conceptual model of lateral landfill gas migration in the geological layer. Prior to drilling new boreholes on the site, a preliminary simplified model will be built with the numerical code TOUGH2-LGM. A description of the geological units, methane flux and the results of the preliminary modeling are presented. The aim of this work is to identify the key parameters used to predict the travel distance of landfill gas

Benchmark calculations for elastic fermion-dimer scattering

We present continuum and lattice calculations for elastic scattering between a fermion and a bound dimer in the shallow binding limit. For the continuum calculation we use the Skorniakov-Ter-Martirosian (STM) integral equation to determine the scattering length and effective range parameter to high precision. For the lattice calculation we use the finite-volume method of L\"uscher. We take into account topological finite-volume corrections to the dimer binding energy which depend on the momentum of the dimer. After subtracting these effects, we find from the lattice calculation kappa a_fd = 1.174(9) and kappa r_fd = -0.029(13). These results agree well with the continuum values kappa a_fd = 1.17907(1) and kappa r_fd = -0.0383(3) obtained from the STM equation. We discuss applications to cold atomic Fermi gases, deuteron-neutron scattering in the spin-quartet channel, and lattice calculations of scattering for nuclei and hadronic molecules at finite volume.Comment: 16 pages, 5 figure

Laparoscopic transperitoneal retromascular (sublay) mesh repair in cure of ventral hernias: first experiences

Catedra Chirurgie nr.5, Universitatea de Stat de Medicină și Farmacie „Nicolae Testemiţanu”, Spitalul Clinic Militar Central, Chişinău, Republica Moldova, Al XIII-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” și al III-lea Congres al Societății de Endoscopie, Chirurgie miniminvazivă și Ultrasonografie ”V.M.Guțu” din Republica MoldovaIntroducere: Poziționarea laparoscopică, retromusculară (sublay) a plasei chirurgicale. Material și metode: În clinica chirurgie Nr 5, (SCMC), în anii 2018-2019 au fost supuși curei laparoscopice pentru hernii ventrale 8 pacienți, 4 femei și 4 barbați. Vîrsta medie 25-70 ani. Pentru protezare s-a folosit plasa din polipropilen light, mai mare cu 5 cm decât defectul herniar pe toate dimensiunile. Proteza a fost amplasată retromuscular, prin abord laparoscopic transperitoneal. Fixarea plasei sa asigurat prin aplicarea agrafelor helicoidale nerezorbabile de ø 4 mm, plasate la 1cm de marginea protezei. Algometria sa efectuat cu utilizarea scalei analog vizuale (VAS). Rezultate: Defectul herniar a avut un diametru median de 3,7 cm. La toți pacienți defectul herniar a fost suturat prin aplicarea suturii intracorporale. Din particularități intraoperatorii se menționează: reducerea conținutului sacului herniar, adezioliză, controlul hemoragiei din adeziuni și decolarea peritoneului și tunicii retromusculare prin incizie longitudinală. Durata medie a intervențiilor a fost de 45 min (35-65 min). În perioada postoperatorie complicații nu au fost semnalate. Sindromul dolor postoperator a fost minim (VAS 1 – 3), complicații parietale absente. Durata mediana de spitalizăre 3,1 zile. În perioada postoperatorie la distanța nu s-au constatat dureri și neuropatii, dereglări de tranzit intestinal, recidive herniare. Concluzii: Cura laparoscopică intraperitoneală retromusculară (sublay) a herniilor ventrale cu aplicarea protezei din polipropilen este o metodă sigură și miniminvazivă, cu costuri reduse la consumabile. Amplasarea retromusculară a plasei exclude aderențele parietoviscerale și complicațiile parietale, asigurând reintegrarea socio-profesională rapidă. Avantajele expuse argumentează perspectivele utilizării tehnicii laparoscopice retromusculare în cura herniilor ventrale.Introduction: Transperitoneal retromuscular sublay positioning of a surgical mesh. Materials and methods: Within period of 2018-2019, 8 retromuscular hernia repairs have been performed on the group of 8 patients diagnosed with ventral hernias, 4 male and 4 female. The overall age was 47,2 years (range 25 - 70). Polypropylene mesh has been utilized for repair. The mesh overlaped the defect with 5 cm. The fixation technique was ensured by applying ø 4 mm non-resorbable spiral tacks plaid up to 1cm from the edge of the prosthetic mesh. Algometry was performed using visual analog scale (VAS). Results: The mean diameter of the hernia defect was 3.7 cm. In all cases the hernia defect has been closed by applying intracorporeal suture. The intraoperative features were: reduction the hernia sac content, removal of adhesions, control of the bleeding with peritoneum and posterior rectus are opened by a longitudinal incision. The mean time of operations was 45 min. In postoperative period there no reported complications. In the distance postoperative period were not found pain and local neuropathy, bowel disorders, hernia recurrences. Conclusions: Laparoscopic transperitoneal retromuscular hernia repair is a safe and minimally-invasive procedure with low cost of consumables. Retromuscular location of the prosthesis exclude the risk of the parietovisceral adhesions and complications ensuring quick socio-professional reintegration. The exposed advantages argument the use of transperitoneal retromuscular procedure in the ventral hernia repair

Exact Solutions to the Sine-Gordon Equation

A systematic method is presented to provide various equivalent solution formulas for exact solutions to the sine-Gordon equation. Such solutions are analytic in the spatial variable $x$ and the temporal variable $t,$ and they are exponentially asymptotic to integer multiples of $2\pi$ as $x\to\pm\infty.$ The solution formulas are expressed explicitly in terms of a real triplet of constant matrices. The method presented is generalizable to other integrable evolution equations where the inverse scattering transform is applied via the use of a Marchenko integral equation. By expressing the kernel of that Marchenko equation as a matrix exponential in terms of the matrix triplet and by exploiting the separability of that kernel, an exact solution formula to the Marchenko equation is derived, yielding various equivalent exact solution formulas for the sine-Gordon equation.Comment: 43 page

The advantages of the laparoscopic approach in operative management of the destructive acute appendicitis

Catedra de chirurgie nr. 5, Universitatea de Stat de Medicină și Farmacie „Nicolae Testemiţanu”, Spitalul Clinic Militar Central, Chişinău, Republica Moldova, Al XIII-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” și al III-lea Congres al Societății de Endoscopie, Chirurgie miniminvazivă și Ultrasonografie ”V.M.Guțu” din Republica MoldovaIntroducere: În ultimul deceniu apendicectomia laparoscopică a devenit standardul de aur în terapia apendicitei acute (AA). Lucrarea relevă rezultatele apendicectomiilor laparoscopice (AL) în AA pe un lot de 118 de pacienți în perioada anilor 2011-2019 Material și metode: În perioada ianuarie 2011-2019 au fost efectuate 118 de AL. Repartiția după sex a evidențiat o predominarea patologiei la femei în coraport B/F – 1:1.7. Vîrsta pacienților a variat de la 18 pînă la 60 de ani, constituind în medie 32,3±11,5 ani. Intraoperator a fost constatat: AA flegmonoasă (n=87), AA gangrenoasă (n=12), și AA perforată cu abces localizat (n=9), perforația apendicelui cu peritonită generalizată (n=6) și infiltrat apendicular (n=4). Tehnica operatorie AL include: poziționarea trocarelor cu instalarea capnoperitoneului, explorarea cavității peritoneale, secționarea mezoapendicelui, ligatura, secționarea apendicelui, și înlăturarea lui. La 45 pacienți prelucrarea bontului a fost efectuată prin metoda ligaturală, iar la 73 a fost realizată tehnica Semm. Rezultate: Durata medie a intervenției a constituit 47,2±18,1 min. (interval 35-78). Algometria postoperatorie a relevat prezența sindromului algic redus. Mediana perioadei de spitalizare a constituit 3 zile cu reîntoarcerea în cîmpul muncii pînă la 10 zile. Rata comună a infecților plăgilor chirurgicale în cadrul grupului AL a fost de 3,38%. Concluzii: Avantajele AL față de cea clasică sunt: diagnosticul cert în cazurile echivoce; intervenție optimă în apendicele ectopic; dializa peritoneală ”la cerere”; incidența redusă a complicațiilor în plăgile postoperatorii, perioada de recuperare mai rapidă și beneficiul cosmetic.Background: Over the last 10 years the use of videoendoscopic approach has been revolutionary expanded into surgical practice. Mounting evidence supports the use of laparoscopic techniques for the diagnosis and treatment of the destructive forms of appendicitis (DA). This paper reveals the results of laparoscopic appendectomies (LA) in DA on a group of 118 patients over the period of 8 years (2011-2019). Methods and materials: From 2011 until 2019 118 LA were performed. The gender distribution revealed a predominance of the pathology in women with a ratio M / F-1: 1.7. The age of patients varied from 18 to 60 years, averaging 32.3±11.5 years. Intraoperative were found: phlegmonous appendicitis (n = 87), gangrenous appendicitis (n = 12), perforated appendicitis with localized abscess (n = 9), perforated appendicitis with generalized peritonitis (n = 6) and appendiceal mass (n= 4). The LA operative technique includes trocars application and CO2 - peritoneum achievement, transabdominal exploration, skeletization of the appendix, ligatures, appendix base ligation with a pre-knotted Roeder-loop, and appendix removal. The appendix stump was inverted in the cecum according to Semm in 73 patients; the ligature technique was applied in 45 patients. Results: The mean operating time was 47.2±18.1 min (range 35-78). The postoperative algometry revealed a decreased presence of postoperative pain syndrome. The mean length of hospital stay was 3 days. Patients returned to work in less than 10 days. Pooled mean surgical wound infection (SWI) rate within the LA group was 3.38%. Conclusions: The LA provides obvious advantages including: definitive diagnosis in equivocal cases; optimal intervention in ectopic appendix; adequate peritoneal lavage “on demand” following removal of the appendix; reduced SWI rate, rapid recovery and cosmetic benefits

Laparoscopic transabdominal pre-peritoneal approach (TAPP) in groin hernia repair: 10 year experience

Catedra de chirurgie nr. 5, Universitatea de Stat de Medicină și Farmacie „Nicolae Testemiţanu”, Spitalul Clinic Militar Central, Chişinău, Republica Moldova, Al XIII-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” și al III-lea Congres al Societății de Endoscopie, Chirurgie miniminvazivă și Ultrasonografie ”V.M.Guțu” din Republica MoldovaIntroducere: Abordul laparoscopic în cura herniilor inghinale devine intervenție de elecție pe plan mondial. Rămâne actuală problema standardizării tehnicii chirurgicale şi optimizarii rezultatelor acestui procedeu. Material şi metode: În perioada anilor 2008-2018 în Clinică a fost efectuată cura laparoscopică a herniei inghinale la 415 pacienţi (37 bilateral). Repartiţia herniilor conform clasificării L. M. Nyhus: tip II (n=245), tip IIIa (n=109), tip IIIb (n=30), tip IIIc (n=13), typ IV (n=18). A fost utilizată tehnică transabdominală preperitoneală (TAPP). Rezultate: Durata intervenţiei a constituit in medie 40.8±20.07 minute, fiind mai lungă pentru hernii recidivante 80±40.9 min (60-180) şi bilaterale 75.7±20.5 min (65-140). Mediana spitalizării 3 zile, reîntoarcerea în cîmpul muncii – sub 10 zile. Incidentele intraoperatorii au fost corectate laparoscopic. Conversia efectuată la doi pacienti. Nu au fost constatate cazuri de infecţie în plaga postoperatorie. Aprecierea rezultatelor tratamentului chirurgical la distanţă a fost realizată la 337 pacienţi. Pentru evaluarea durerii la pacienţii cu diagnosticul hernie inghinală a fost utilizată scala de evaluare numerică NRS-10. În perioada postoperatorie au prevalat pacienţi cu sindrom algic redus (NRS 1-3). Algoparestezia postoperatorie persistentă a fost diagnosticată la 6 pacienţi. Recidiva herniei a fost înregistrată la 3 pacienţi, în ambele cazuri recidiva a fost corectată laparoscopic. Concluzii: Experienţa noastră confirmă posibilitatea utilizării procedeului TAPP la diferite tipuri de hernie inghinală. Acumularea experienţei permite de a lărgi indicaţiile pentru abordul laparoscopic la pacienţii cu hernii bilaterale, glisante şi recurente. Avantajele hernioplastiei laparoscopice sunt: micşorarea sindromului algic postoperator, reintegrarea socioprofesională rapidă şi numărul redus de complicaţii parietale.Background: the transabdominal pre-peritoneal procedure (TAPP) represents one of the most popular techniques used for inguinal hernia repair. The analysis of the reported cases helps to standardize the relatively new laparoscopic technique and to improve the overall results. Methods and materials: The group of 415 patients underwent laparoscopic hernia repair (37 bilateral) for the period 2008-2018. According to L. M. Nyhus classification, the groin hernias were classified as type II (n=245), type IIIa (n=109), type IIIb (n=30), type IIIc (n=13), type IV (n=18). The TAPP procedure was utilized. Results: The mean operating time was 40.8±20.07 minutes, being statistically longer for recurrent hernias 80±40,9 min (range 60- 180) and bilateral hernias 75,7±20,5 min (range 65-140). The average length of hospital stay was 3 days. Patients returned to work in an average of 10 days. The postoperative morbidity rate was 2.2%. The majority of intraoperative incidents (intraoperative hemorrhage n=5) were solved laparoscopically without sequelae. Two cases were converted to Lichtenstein repair. Patients were evaluated at a median follow up of 24 month (range 12-36 month). A total of 337 patients were assesssed for long-term outcomes. Pain was assessed with Numerical Rating Scale (NRS-10). The vast majority of post-operative patients had minor pain manifestation of pain (NRS 1-3). We observed 6 cases of persistent inguinal pain. The hernia recurrence was developed in 3 patients and has been corrected via laparoscopic approach. Conclusions: While laparoscopic hernia repair requires a lengthy learning curve, it represents safe and valid alternative to open hernia repairs and can be effectively used for bilateral, recurrent and sliding hernias. The advantages of laparoscopic repair include less postoperative pain, faster return to normal activities and low wound infection rate

The use of endoscopic ligation in the treatment and prophylaxis of bleeding from esophageal varices in patients with liver cirrhosis and portal hypertension

Scopul lucrării. Hemoragia din varicele esofagiene și gastrice reprezintă una din cele mai grave complicații la pacienții cu hipertensiune portală cirogenă. Una din metodele eficiente de prevenire și stopare a recurenței hemoragiilor din varicele esofagiene este ligaturarea endoscopică cu aplicarea benzilor elastice. Scopul este analiza rezultatelor obținute în tratamentul hemoragiilor din varicele esofagiene la pacienții cu ciroză hepatică și hipertensiune portală prin metoda de ligaturare endoscopică. Materiale şi metode. Studiul a inclus 110 pacienți cu vârstă cuprinsă între 37-87 ani, diagnosticați cu ciroză hepatică și hipertensiune portală, la care a fost utilizată ligaturarea endoscopică a varicelor esofagiene. Profilaxia primară a hemoragiilor din varicele esofagiene prin ligaturare endoscopică a varicelor esofagiene a fost efectuată la 69 (62,72%) pacienți, iar hemostaza și profilaxia secundară - la 41 (37,28%) pacienți cu varice esofagiene gradul II-III și esofagită erozivă. Rezultate. La 13 pacienți (11,81%), care prezintă hemoragie activă variceală, în primele 24-36 ore prin ligaturare endoscopică s-a obținut hemostaza. Dintre pacienții la care a fost efectuată ligaturarea profilactică în prevenirea primului episod de hemoragie, doar la 4 pacienți (3,63%) au avut loc hemoragii minore, care au fost stopate prin metode conservative de tratament. La 5 pacienți (4,54%) peste 6 luni, din cauza recidivei hemoragiei, a fost repetată ligaturarea endoscopică. Alte complicații sau recidiva hemoragiilor din varicele esofagiene la pacienții supravegheați nu au fost depistate. Concluzii. În urma utilizări ligaturării endoscopice cu benzi elastice a varicelor esofagiene complicații majore sau sistemice nu s-au înregistrat, ceea ce semnifică o rată înaltă de reușită a metodei respective.Aim of study. Hemorrhage from esophageal and gastric varices is one of the most serious complications in patients with cirrhogenic portal hypertension. One of the effective methods of preventing and stopping the recurrence of bleeding from esophageal varices is endoscopic ligation with the application of elastic bands. The purpose is the analysis of the results obtained in the treatment of bleeding from esophageal varices in patients with liver cirrhosis and portal hypertension by the endoscopic ligation method. Materials and methods. The study included 110 patients aged 37-87 years, diagnosed with liver cirrhosis and portal hypertension, who underwent endoscopic ligation of esophageal varices. Primary prophylaxis of bleeding from esophageal varices by endoscopic ligation of esophageal varices was performed in 69 (62.72%) patients, hemostasis and secondary prophylaxis - in 41 (37.28%) patients with grade II-III esophageal varices and erosive esophagitis. Results. In 13 patients (11.81%), who had active variceal hemorrhage, hemostasis by endoscopic ligation was achieved in the first 24-36 hours. Among the patients in whom prophylactic ligation was performed to prevent the first episode of hemorrhage, only 4 patients (3.63%) had minor hemorrhages, which were stopped by conservative treatment methods. In 5 patients (4.54%) due to recurrence of bleeding, endoscopic ligation was repeated over 6 months, Other complications or recurrence of bleeding from esophageal varices in the monitored patients were not detected. Conclusions. In the use of elastic band ligation of esophageal varices, no major or systemic complications were recorded, which signifies a high success rate of this method

Improving the sensitivity of future GW observatories in the 1-10 Hz band: Newtonian and seismic noise

The next generation gravitational wave interferometric detectors will likely be underground detectors to extend the GW detection frequency band to frequencies below the Newtonian noise limit. Newtonian noise originates from the continuous motion of the Earth’s crust driven by human activity, tidal stresses and seismic motion, and from mass density fluctuations in the atmosphere. It is calculated that on Earth’s surface, on a typical day, it will exceed the expected GW signals at frequencies below 10 Hz. The noise will decrease underground by an unknown amount. It is important to investigate and to quantify this expected reduction and its effect on the sensitivity of future detectors, to plan for further improvement strategies. We report about some of these aspects. Analytical models can be used in the simplest scenarios to get a better qualitative and semi-quantitative understanding. As more complete modeling can be done numerically, we will discuss also some results obtained with a finite-element-based modeling tool. The method is verified by comparing its results with the results of analytic calculations for surface detectors. A key point about noise models is their initial parameters and conditions, which require detailed information about seismic motion in a real scenario. We will describe an effort to characterize the seismic activity at the Homestake mine which is currently in progress. This activity is specifically aimed to provide informations and to explore the site as a possible candidate for an underground observatory. Although the only compelling reason to put the interferometer underground is to reduce the Newtonian noise, we expect that the more stable underground environment will have a more general positive impact on the sensitivity.We will end this report with some considerations about seismic and suspension noise

Developing national obesity policy in middle-income countries: a case study from North Africa

Background The prevalence of overweight and obesity is a rapidly growing threat to public health in both Morocco and Tunisia, where it is reaching similar proportions to high-income countries. Despite this, a national strategy for obesity does not exist in either country. The aim of this study was to explore the views of key stakeholders towards a range of policies to prevent obesity, and thus guide policy makers in their decision making on a national level. Methods Using Multicriteria Mapping, data were gathered from 82 stakeholders (from 33 categories in Morocco and 36 in Tunisia) who appraised 12 obesity policy options by reference to criteria of their own choosing. Results The feasibility of policies in practical or political terms and their cost were perceived as more important than how effective they would be in reducing obesity. There was most consensus and preference for options targeting individuals through health education, compared with options that aimed at changing the environment, i.e. modifying food supply and demand (providing healthier menus/changing food composition/food sold in schools); controlling information (advertising controls/mandatory labelling) or improving access to physical activity. In Tunisia, there was almost universal consensus that at least some environmental-level options are required, but in Morocco, participants highlighted the need to raise awareness within the population and policy makers that obesity is a public health problem, accompanied by improving literacy before such measures would be accepted. Conclusion Whilst there is broad interest in a range of policy options, those measures targeting behaviour change through education were most valued. The different socioeconomic, political and cultural contexts of countries need to be accounted for when prioritizing obesity policy. Obesity was not recognized as a major public health priority; therefore, convincing policy makers about the need to prioritize action to prevent obesity, particularly in Morocco, will be a crucial first step