Effects of Laser Irradiation on Caries Prevention

INTRODUCTION: Although dental caries is a preventable disease, it is still common and remains a public health problem. One of the potentially effective preventive measures is the use of lasers. The purpose of this study was to review the studies about use of laser irradiation on the inhibition of carious lesions and the effectiveness of different commercial laser type (Nd:YAG, CO2, and Argon).METHODS: A literature search included journal databases, existing systematic reviews, and studies identified by content experts. Studies meeting inclusion criteria were assessed for quality.RESULTS: Some studies have demonstrated the potential preventive effect of laser irradiation on sound enamel; the effect of irradiation on white spot lesions is still unclear. The effects of irradiating demineralized enamel surfaces coupled with the use of topical fluoride application is also still unclear and further research needs to be conducted in this area. Laser irradiation alone can significantly enhance acid resistance of sound enamel surfaces and prevent caries progression.CONCLUSION: Combined use of topical fluoride application and laser irradiation on sound enamel surfaces has provided the best protection against caries initiation and progression. Laser irradiation was of limited value in managing incipient carious lesions. Argon laser use may be easier clinically due to its large and visible beam diameter, which allows for irradiation of the whole surface of the tooth instead of the overlapping and time consuming pattern of the CO2 laser

The effect of knowledge sharing on technology acceptance among physicians

The healthcare sector has utilized a variety of technologies such as clinical IT to improve effectiveness of healthcare professionals and the quality of health care delivery. Having unused clinical IT appears a strict challenge for hospitals. Meanwhile, there is enough evidence to state that healthcare professionals have not fully adopted and used clinical IT. The main objective of this study is to identify factors which influence healthcare professionals’ adoption of clinical IT. This study comes up with a modified technology acceptance model (TAM) to integrate both the special characteristic of healthcare professionals and unique feature of clinical IT. This study investigates whether attitude toward knowledge determines healthcare professionals’ intention to use clinical IT. The proposed model has been developed to mainly deal with IT adoption issues among healthcare professionals in hospitals. A survey has been done to evaluate the model among 300 healthcare professionals in Malaysia. The structural equation model has been used to test the model in this context. The results reveal the significant role of perceived threat to professional autonomy, attitude toward knowledge sharing, perceived usefulness and perceived ease of use in shaping healthcare professionals’ intention to use clinical IT in Malaysia. The proposed model can explain 48% of the variance of physicians’ intention to accept clinical IT

Groundwater Recharge Assessment in the Karstic Aquifers of North Khorasan, Iran in APLIS Method

In order to optimize consumption, maintenance and control of underground water, an estimation of the groundwater recharge is highly important. Therefore, this research investigates the aquifers in North Khorasan province using APLIS (Applied Physics Laboratory Ice Station) based on a GIS. For this purpose, several significant hydrogeological parameters affecting groundwater recharge including altitude, slope, lithology, soil type and infiltration are considered. Therefore, corresponding layers for these parameters were provided and prioritized. In the end and after integrating the data, the recharge rate was measured qualitatively and different regions were mapped accordingly. The results indicate that the annual average values on a 30-year timescale in karst formations of the North Khorasan vary between 103 mm and 362 mm, with the mean value of 192 mm. Minimum, maximum and mean recharge rates of aquifer in the study area are 42 %, 73 % and 54 %, respectively. Also, aquifer recharge potential in 83 % of the karst formations is moderate while it is high for the remaining. Low recharge regions correlate to lower karst limestone and dolostone areas in the lower altitudes while high recharge regions represent upper karst limestone and dolostone areas, especially in the high altitudes.Key words: Groundwater resource management, Recharge, APLIS, GIS, karst, North Khorasan. Ocenjevanje napajanja podzemne vode v kraških vodonosnikih v severnem Horasanu, v Iranu, z uporabo metode APLIS Za optimizacijo porabe, vzdrževanja in nadzora nivoja podzemne vode je ocena napajanja vodonosnika zelo pomembna. Zato raziskava z uporabo metode APLIS, ki temelji na GIS, raziskuje vodonosnike v provinci Severni Horasan v Iranu. Pri tem smo upoštevali več pomembnih hidrogeoloških parametrov, ki vplivajo na napajanje vodonosnika, vključno z nadmorsko višino, naklonom, litologijo, tipom tal in infiltracijo. Za vsakega od parametrov smo pripravili informacije v ustreznih oblikah. Po obdelavi in integraciji podatkov smo izračunali hitrost polnjenja vodonosnika. Različne regije smo ustrezno ovrednotili. Rezultati kažejo, da se v kraških formacijah Severnega Horasana letne povprečne vrednosti v 30-letnem časovnem obdobju gibljejo med 103 mm in 362 mm, s povprečno vrednostjo 192 mm. Najmanjše, najvišje in povprečne stopnje polnjenja vodonosnika v študijskem območju so 42-, 73- in 54-odstotne. Tudi potencial polnjenja vodonosnika je v 83-odstotnih kraških formacij ocenjen kot zmeren, za preostale predele je ocenjen kot visok. Območja z nizkim potencialom polnjenja so povezana z nižje ležečimi zakraselimi apnenci in dolomiti, višje ležeča območja predstavljajo apnenci in dolomiti z višjim potencialom polnjenja. Ključne besede: upravljanje podzemnih vodnih virov, napajanje, APLIS, GIS, kras, Severni Horasan.

Jursprudentical and Legal Critique of “Tatarros” and “Avoidance of Taghut” in the Foundations of Takfiri Terrorism

Takfiri terrorism, as a political phenomenon for those claiming power in form of religious groups is expanding in Islamic countries and has become the greatest challenge for the Islamic world. Misuse of jurisprudential rules named "Tatarros" and "Avoidance of Taghut" is the most abject mental and practical approach that is being practised by this group. The present article adopts library and descriptive-analytical methods to examine major principles of Takfiri terrorism from the perspective of jurisprudence and law. The purpose of this study is to prove that the main principles of Takfiri terrorism, namely the jurisprudential rule of "Tatarros" and "Avoidance of Taghut", seek aggression and other forms of terror in Islamic countries and that the killing of Muslims by Takfiris is unrelated to the rule of Tatarros. The question is what conditions govern these rules according to Islamic jurists and whether these rules entail suicide attacks and the killing of civilians

ANALIZA POUZDANOSTI STROJEVA ZA PUNOPROFILNI ISKOP TUNELA PRIMJENOM SIMULACIJSKE METODE MONTE CARLO

The high boring capability of full-face tunnel boring machines, especially in urban tunnels, has led to their increased use in tunnel excavation in various and unfavourable geological conditions. Therefore, many efforts have been made to predict and improve the performance of these machines. In this regard, most of the previous studies have focused on the effect of geological and mechanical properties of rock or soil. However, delays due to the maintenance and repair of these machines, which contribute to a major share of unwanted and unpredicted stops at work, have not been considered. Reliability analysis is a practical method based on studying the behaviour of breakdowns and maintenance of machines and systems. This approach can be suggested as part of the appropriate planning for machine maintenance and consequently reducing downtime and costs. In this way, it is possible to identify weaknesses and critical points of a machine or system of the boring process. In the present study, the reliability of the full-face tunnelling machine was analysed with the Monte Carlo simulation method. The studied machine is divided into 5 subsystems including mechanical, electrical, hydraulic, water and compressed air subsystems. Using breakdown data of about 24 months of boring operation, the reliability of each subsystem was simulated and evaluated. Eventually, the reliability of the boring machine was simulated using the Kamat-Riley (K-R) method. The results showed that if no maintenance operation is performed on the subsystems, the overall reliability of the boring machine will decline to zero after about 38 hours of continuous boring operation. Finally, to improve the overall reliability of the boring machine, based on accomplished reliability analysis, we suggest an effective preventive maintenance and repair system for keeping the machine in optimal operating conditions for a longer period.Visoka učinkovitost strojeva za bušenje punoga profila tunela, posebno u gradskim tunelima, dovela je do njihove sve veće upotrebe u iskopu tunela u različitim i nepovoljnim geološkim uvjetima. Stoga su uloženi veliki napori sa svrhom predviđanja i poboljšanja učinkovitosti ovih strojeva. Većina prethodnih studija bila je usmjerena na utjecaj geoloških i mehaničkih svojstava stijene ili tla. Međutim, kašnjenja zbog održavanja i popravka ovih strojeva, koji doprinose velikomu udjelu neželjenih i nepredviđenih zaustavljanja pri radu, nisu uzeta u obzir. Analiza pouzdanosti praktična je metoda koja se temelji na proučavanju utjecaja kvarova i održavanja strojeva i sustava. Ovaj pristup može poslužiti za prikladno planiranje održavanja strojeva i posljedično smanjenje zastoja i troškova. Na taj način moguće je identificirati slabosti i kritične točke stroja ili sustava procesa bušenja. U ovome je istraživanju pouzdanost stroja za probijanje tunela analizirana primjenom simulacijske metode Monte Carlo. Stroj na kojemu je provedena analiza podijeljen je u 5 podsustava uključujući mehanički, električni, hidraulički te podsustave za komprimirani zrak i vodu. Koristeći se podatcima o kvarovima za oko 24 mjeseca bušenja simulirana je i procijenjena pouzdanost svakoga podsustava. Na kraju je simulirana pouzdanost stroja za bušenje korištenjem Kamat-Rileyjeve (K-R) metode. Rezultati su pokazali da ako se na podsustavima ne provodi operacija održavanja, ukupna pouzdanost stroja za bušenje past će na nulu nakon otprilike 38 sati neprekidnoga rada bušenja. U konačnici, radi poboljšanja sveukupne pouzdanosti stroja za bušenje, na temelju provedene analize pouzdanosti predlažemo učinkovit sustav preventivnoga održavanja i popravaka za održavanje stroja u optimalnim radnim uvjetima dulje vrijeme