The large number of pollutants in water requires the application of various water treatment techniques. However, it is timeconsuming, costly, and laborious to experimentally determine effective techniques for pollutant removal. As an alternative solution, quantitative structure−property relationship (QSPR) modeling has been applied to water treatments, including adsorption, membrane filtration, coagulation, ozonation, the Fenton reaction, photolysis, and photocatalysis. This work is a critical review of the application of QSPR models to water treatment. This modeling approach has proven to be useful for both significantly reducing the experimental load and predicting the treatment characteristics and performance, which are based on the chemical structures involved, the availability of molecular properties with minimal computational cost, and the applicability for regulatory purposes. Although current studies can serve as a basis for further model development, methods of testing the applicability of QSPR models under environmentally relevant conditions have not been explored. We also examine current priorities in ongoing research and the potential development of QSPR models for water treatment applications.

In order to precisely establish the bio-and chronostratigraphic position of several levels of the Silurian-Devonian succession of Bolivia, with respect to the International Time Scale, additional Silurian and Devonian localities belonging to the Eastern Cordillera and the Interandean Zone areas have been recently revised and sampled, both for macrofossils and palynomorphs. Specifically, the localities are Ñuñumayani, and Muruhuta from the late Silurian-early Devonian time interval. Correlations with other fossiliferous localities are discussed, namely Huacallani and Rumicorral. A new outcrop yielding Middle Devonian tabulate corals at Pisacaviña is described; its faunal content is described, and compared with the historical coral collection. As a result, it appears clearly that the Silurian-Devonian Bolivian fauna needs a thorough revision, as well as the selection of stratigraphically significant macrofossils. Besides macrofossils, the analysis of palynomorph assemblages is significant in establishment of both intra-Bolivian and international correlations before any reliable biogeographic reconstruction is done. This paper records the first discovery of a plant of the genus Protolepidodendron from the Devonian of Bolivia. An ostracod assemblage from Pisacaviña is described, illustrated, and discussed for the first time; it suggests an Early Devonian or an Eifelian age. Newly described taxa include the coral Parastriatopora boliviana sp. nov., and the chonetoidean brachiopods Sanjuanetes glemareci sp. nov., and Kentronetes giae sp. nov. •

The highly productive Permian Basin requires wells with high dogleg severity (DLS) curve and long lateral sections. After many years of development and participation by all major industry players, most 8.5in size wells are still being drilled using two bottomhole assemblies (BHAs); one for the curve and a second for the extended lateral section. This increases cost, time, and risks. With development of our new solution, curve and lateral sections of Permian wells can now be consistently drilled in one run. Using in-house digital modeling and dynamic drilling simulation software of the complete drilling system and complex lithology profiles, design attributes were evaluated for directional performance before initial prototypes were created. These models increased efficiency and cost savings in the design process. Analysis revealed that shortening the distance from the RSS pad actuators to the bit (L1), increases the build-rate capability, increases the DLS output in the curve section, and provides tight trajectory control in long laterals. The system design also has a proprietary bit box connection and polycrystalline diamond compact (PDC) cutters on the bias unit. Prototype testing was done on high-DLS curve and lateral wells with major operators delivering wells per client requirements. The new solution successfully landed high DLS curve sections in 14 wells. The solution achieved a new milestone of delivering the 8.5-in curve on target and much faster than the conventional motor in the same application. After the curve sections the same BHA drilled into the long lateral section without making a trip between the curve and lateral sections. Several records were broken in some of these 14 wells, including 19% more daily footage than the previous record. Almost all these wells were also drilled using a remote operations center utilizing latest digital capabilities, reducing onsite footprint. Based on the most conservative figures from field test results and projected usage, the increased efficiency and faster well delivery time can significantly impact sustainability, reducing CO2 emissions per well drilled by this new solution.

México es afectado periódicamente por fuertes inundaciones que inhiben su desarrollo económico. Medidas de adaptación y gestión de riesgos se basan sobre todo en la evaluación de costos, por lo que ésta debe ser comprehensiva. Este artículo evalúa los costos económicos totales ocasionados por el huracán Alex en el estado de Nuevo León en el año de 2010, fenómeno natural que fue catalogado como el más devastador de los últimos 50 años. Así, se aplicó por vez primera, para un caso en el país, una metodología que considera, además de los costos directos (daños materiales), los costos indirectos (afectaciones a la producción) en los sectores económicos de la región afectada, basada en el modelo insumo producto (MIP).