diff --git a/numass-main/src/main/groovy/inr/numass/LaunchGrindShell.groovy b/numass-main/src/main/groovy/inr/numass/LaunchGrindShell.groovy
index 36b16f69..87beebfa 100644
--- a/numass-main/src/main/groovy/inr/numass/LaunchGrindShell.groovy
+++ b/numass-main/src/main/groovy/inr/numass/LaunchGrindShell.groovy
@@ -17,17 +17,18 @@ String cfgPath = cli.parse(args).c;
 println "Loading config file from $cfgPath"
 println "Starting Grind shell"
 
-if (cfgPath) {
-    try {
-        GrindTerminal.system().launch {
+
+try {
+    GrindTerminal.system().launch {
+        if (cfgPath) {
             GrindWorkspaceBuilder numass = new GrindWorkspaceBuilder(context).read(new File(cfgPath))
             bind("numass", numass)
+        } else {
+            println "No configuration path. Provide path via --config option"
         }
-    } catch (Exception ex) {
-        ex.printStackTrace();
-    } finally {
-        Global.terminate();
     }
-} else {
-    println "No configuration path. Provide path via --config option"
-}
\ No newline at end of file
+} catch (Exception ex) {
+    ex.printStackTrace();
+} finally {
+    Global.terminate();
+}
diff --git a/numass-main/src/main/groovy/inr/numass/scripts/Underflow.groovy b/numass-main/src/main/groovy/inr/numass/scripts/Underflow.groovy
index f0b5c6d1..1824a7bd 100644
--- a/numass-main/src/main/groovy/inr/numass/scripts/Underflow.groovy
+++ b/numass-main/src/main/groovy/inr/numass/scripts/Underflow.groovy
@@ -15,8 +15,8 @@ import inr.numass.storage.NumassStorage
 import inr.numass.utils.UnderflowCorrection
 
 //File rootDir = new File("D:\\Work\\Numass\\data\\2016_10\\Fill_1")
-//File rootDir = new File("D:\\Work\\Numass\\data\\2016_10\\Fill_2_wide")
-File rootDir = new File("D:\\Work\\Numass\\data\\2017_01\\Fill_2_wide")
+File rootDir = new File("D:\\Work\\Numass\\data\\2016_10\\Fill_2_wide")
+//File rootDir = new File("D:\\Work\\Numass\\data\\2017_01\\Fill_2_wide")
 
 NumassStorage storage = NumassStorage.buildLocalNumassRoot(rootDir, true);
 
diff --git a/numass-main/src/main/java/inr/numass/models/sterile/NumassResolution.java b/numass-main/src/main/java/inr/numass/models/sterile/NumassResolution.java
index b19a1f33..fcb4e418 100644
--- a/numass-main/src/main/java/inr/numass/models/sterile/NumassResolution.java
+++ b/numass-main/src/main/java/inr/numass/models/sterile/NumassResolution.java
@@ -5,16 +5,21 @@
  */
 package inr.numass.models.sterile;
 
+import hep.dataforge.context.Context;
+import hep.dataforge.maths.MathPlugin;
 import hep.dataforge.meta.Meta;
 import hep.dataforge.stat.parametric.AbstractParametricBiFunction;
 import hep.dataforge.values.NamedValueSet;
 import inr.numass.models.ResolutionFunction;
+import inr.numass.utils.ExpressionUtils;
 import org.apache.commons.math3.analysis.BivariateFunction;
 
+import java.util.HashMap;
+import java.util.Map;
+
 import static java.lang.Math.sqrt;
 
 /**
- *
  * @author <a href="mailto:altavir@gmail.com">Alexander Nozik</a>
  */
 public class NumassResolution extends AbstractParametricBiFunction {
@@ -25,13 +30,28 @@ public class NumassResolution extends AbstractParametricBiFunction {
     private double resB = 0;
     private BivariateFunction tailFunction = ResolutionFunction.getConstantTail();
 
-    public NumassResolution(Meta meta) {
+    public NumassResolution(Context context, Meta meta) {
         super(list);
         this.resA = meta.getDouble("A", 8.3e-5);
         this.resB = meta.getDouble("B", 0);
         if (meta.hasValue("tailAlpha")) {
             //add polinomial function here
-            tailFunction = ResolutionFunction.getAngledTail(meta.getDouble("tailAlpha"), meta.getDouble("tailBeta", 0));
+            double alpha = meta.getDouble("tailAlpha");
+            double beta = meta.getDouble("tailBeta", 0);
+            tailFunction = (double E, double U) -> 1 - (E - U) * (alpha + E / 1000d * beta) / 1000d;
+        } else if (meta.hasValue("tail")) {
+            String tailFunctionStr = meta.getString("tail");
+                if (tailFunctionStr.startsWith("function::")) {
+                    tailFunction = MathPlugin.buildFrom(context).buildBivariateFunction(tailFunctionStr.substring(10));
+                } else {
+                    tailFunction = (E, U) -> {
+                        Map<String, Object> binding = new HashMap<>();
+                        binding.put("E", E);
+                        binding.put("U", U);
+                        binding.put("D", U - E);
+                        return ExpressionUtils.function(tailFunctionStr, binding);
+                    };
+                }
         } else {
             tailFunction = ResolutionFunction.getConstantTail();
         }
diff --git a/numass-main/src/main/java/inr/numass/models/sterile/SterileNeutrinoSpectrum.java b/numass-main/src/main/java/inr/numass/models/sterile/SterileNeutrinoSpectrum.java
index 7e9a0c3e..8c0bd53c 100644
--- a/numass-main/src/main/java/inr/numass/models/sterile/SterileNeutrinoSpectrum.java
+++ b/numass-main/src/main/java/inr/numass/models/sterile/SterileNeutrinoSpectrum.java
@@ -73,7 +73,7 @@ public class SterileNeutrinoSpectrum extends AbstractParametricFunction {
         }
 
         transmission = new NumassTransmission(context, configuration.getMetaOrEmpty("transmission"));
-        resolution = new NumassResolution(configuration.getMeta("resolution", Meta.empty()));
+        resolution = new NumassResolution(context, configuration.getMeta("resolution", Meta.empty()));
         this.fast = configuration.getBoolean("fast", true);
         transRes = new TransRes();
     }
@@ -148,16 +148,16 @@ public class SterileNeutrinoSpectrum extends AbstractParametricFunction {
         }
 
         UnivariateIntegrator integrator;
-        if(fast){
+        if (fast) {
             if (eMax - u < 300) {
                 integrator = NumassIntegrator.getFastInterator();
-            } else if(eMax - u > 2000){
+            } else if (eMax - u > 2000) {
                 integrator = NumassIntegrator.getHighDensityIntegrator();
             } else {
                 integrator = NumassIntegrator.getDefaultIntegrator();
             }
 
-            } else {
+        } else {
             integrator = NumassIntegrator.getHighDensityIntegrator();
         }