Soil compaction oft en occurs in heavily traffi cked turf areas such as golf course putting greens and sports fi elds. Although research exists on benefi ts of proper aerifi cation, insuffi cient data exists quantifying the eff ect of removing, or "impacting," specifi c amounts of surface area per year, number of aerifi cation events per year, or amount of topdressing applied postaerifi cation on turfgrass quality and soil physical properties. Understanding these eff ects was the objective of this study. Th e study was conducted on a 10-yr-old U.S. Golf Association (USGA)-specifi ed TifEagle bermudagrass [Cynodon dactylon (L.) Pers. × C. transvaalensis Burtt Davy] research putting green to evaluate two yearly totals of percent surface area impacted, 15 and 25, summed through one, two, or three aerifi cation events per year, with cores removed. Following aerifi cation, treatments received one of two topdressing rates; the mathematical equivalent of soil removed with aerifi cation or half this rate. Turf quality declined for ~4 wk aft er each aerifi cation event, at which point it typically improved. Increasing number of aerifi cation events per year from one to three reduced bulk density (BD) between 5 and 9%, surface hardness between 5 and 19%, and thatch-mat organic matter content 10% in Year 2. Infi ltration rates were highest in single aerifi cation event treatments during the same year. Overall, increasing amount of surface area impacted and number of aerifi cation events per year improved soil physical properties. Reducing frequency of aerifi cation while impacting the same amount of surface area per year increased overall visual turfgrass quality while not yielding similar improvements in soil physical properties.

Three polymers of pharmaceutical/medical relevance are synthesized: poly(glycidol) (PG), poly(glycidol)‐g‐L‐lactide (PG‐g‐La), and poly(glycidol)‐g‐glycolide (PG‐g‐Gly). Because the thermal stability of these polymers is an essential factor of their processing and practical application, the study focuses on kinetic and mechanistic aspects of non‐oxidative thermal degradation. The study is conducted by combining thermogravimetry, Fourier transform infrared spectroscopy, and isoconversional kinetic analysis. It is found that PG degrades in a single mass loss step, whereas, PG‐g‐La and PG‐g‐Gly in two. It is demonstrated that the first step in degradation of PG‐g‐La and PG‐g‐Gly is associated with decomposition of the pendant groups and the second is due to degradation of the PG backbone.magnified image

Poly(lactide)s and poly(lactide-co -glycolide)s with different number of arms are synthesized from L -lactide and glycolide monomers using stannous(II) 2-ethylhexanoate and alcohols containing 1, 2, 25, and 51 hydroxyl groups. 1-dodecanol is used to produce the 1-arm polymer, poly(ethylene glycol) for the 2-arm polymer, and polyglycidols of appropriate molecular weight are used to initiate the 25-and 51-arm branched polyesters. The polymers are characterized by 1 H NMR and GPC. The thermal properties of the polymers are studied using DSC. Their degradation behavior is indestigated using a combination of thermogravimetry, FTIR spectroscopy, and isoconversional kinetic analysis.

Doveweed is a problematic weed of lawns and sod production, as well as golf course roughs, fairways, and tees. End-user reports of selective POST control options are inconsistent and control is often short-lived. In addition, inconsistent control with non-selective herbicides such as glyphosate is common. The goals of this research were: (1) evaluate selective POST doveweed control options in ‘Tifway’ hybrid bermudagrass turf; (2) compare efficacy of single vs. sequential applications of selective POST herbicides; (3) quantify doveweed tolerance to glyphosate; and (4) quantify recovery of foliar applied glyphosate following treatment with a C14-glyphosate solution. A single application of sulfentrazone+metsulfuron; thiencarbazone+iodosulfuron+dicamba or 2,4-D+MCPP+dicamba+carfentrazone; or thiencarbazone+foramsulfuron+halosulfuron provided >60% control 2 weeks after initial treatment (WAIT). A second application of these treatments 3 WAIT improved control 6 WAIT. Two applications of 2,4-D+MCPP+dicamba+carfentrazone or thiencarbazone+foramsulfuron+halosulfuron provided ~80% control 6 WAIT. Doveweed was tolerant to glyphosate application up to 5.68 kgaeha-1. Absorption of 14C-glyphosate was compared between doveweed with cuticle intact, doveweed with a disturbed cuticle, and smooth crabgrass. 14C-glyphosate recovery from the leaf surface of doveweed plants with an intact cuticle was 93.6%. In comparison, 14C-glyphosate recovery from the leaf surface of doveweed plants with a disrupted cuticle and the leaf surface of crabgrass plants was 79.1 and 70.5%, respectively.

The syntheses of a series of substituted polyphosphonates of the type [OP(X)(Ar)O(CH2)12]n (X = O, S, Se; Ar = phenyl, 2,2′‐bithienyl‐5‐yl) are reported. The trueM¯ns for the polyphosphonates range from 1.1 to 4.6 × 104 Da and are significantly higher than those previously reported for polyphosphonates synthesized via polycondensation reactions. Thermal characterization indicates that all of the polymers are in the rubbery state at room temperature and have thermal stabilities as high as 290 °C. The linear absorption spectra, emission spectra, and emission quantum yields of the 2,2′‐bithenyl‐5‐yl substituted polyphosphonates show distinct trends with respect to the chalcogen attached to the phosphorus. Solutions of these polymers show emission at wavelengths ranging from 380 to 400 nm and, depending on the choice of X, the quantum yields are considerably larger than that of 2,2′‐bithiophene. Nonlinear optical measurements of the polyphosphonates with 2,2′‐bithenyl‐5‐yl substituents show that nonlinear absorbance increases with increasing molecular weight of X. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 3663–3674